Tool

Brain Map

How wiring differs

Brains are wired in different ways, and research can show where those differences sit on average. Tap a part of the brain, or pick a way of being wired, to see where research finds differences, what it can feel like, and what helps.

Before you read the map

This is a map of group averages from research. People who share a label differ a lot from each other, and they overlap a great deal with people who do not have it. A scan cannot diagnose anyone, and nothing here is a diagnosis.

Brains change with experience, sleep, support and treatment, so a difference is a snapshot, not a verdict. A difference is not damage, and it is not anyone’s fault.

Some of these are lifelong neurodevelopmental differences: autistic, ADHD and dyslexic wiring. Others are health conditions that can improve: anxiety, depression, trauma and PTSD, and OCD. Both deserve understanding and support, and many people have more than one.

Where this comes from: Maguire et al., 2000; Månsson et al., 2016; Holiga et al., 2019.

A typical gap in the large scan studies below is about a tenth to a fifth of a standard deviation. If both groups are bell-shaped, the two curves overlap by more than 90 percent.

The interactive map needs JavaScript. Here is what it says in plain text, for each way of being wired. Everything below is an average from group studies, with a lot of overlap between groups.

Autistic wiring

A neurodevelopmental difference. Autistic people tend to take in the senses, other people’s signals and routines in their own way. Scan studies find small average differences in several regions, and autistic people vary a great deal from each other.

Sensory cortices (tends to be more variable): Sensory differences are very common, and they run in both directions: some sensations arrive too loud, others barely register. In a pooled analysis the gap was biggest for under-responding, then over-responding. This comes from reports and behavior tests, not from a scan. Evidence: Strong. Ben-Sasson et al., 2009; Robertson and Baron-Cohen, 2017
Thalamus (tends to be connected differently): The thalamus, the relay for the senses, was more strongly connected with several cortical areas in one data set (228 autistic and 228 non-autistic people), mostly in teenagers. Other studies found weaker links in some pathways, so the direction is not settled. Evidence: Early. Woodward et al., 2017
Temporal-parietal areas (tends to be smaller or thinner): The temporal cortex was slightly thinner on average, with the biggest gap around adolescence. The effect was about two tenths of a standard deviation at most. Evidence: Strong. van Rooij et al., 2018
Prefrontal cortex (tends to be larger or thicker): Parts of the frontal cortex were slightly thicker on average, again about two tenths of a standard deviation at most. The pattern changes with age. Evidence: Strong. van Rooij et al., 2018
Basal ganglia (striatum) (tends to be smaller or thinner): The putamen, the nucleus accumbens and the pallidum, which sit in or beside the striatum, were slightly smaller on average, by about a tenth of a standard deviation. Evidence: Strong. van Rooij et al., 2018
Amygdala (tends to be smaller or thinner): Slightly smaller on average, by about a tenth of a standard deviation. Size is not the same as how a region responds. Evidence: Strong. van Rooij et al., 2018
Cerebellum (tends to be smaller or thinner): In a pooled analysis of 17 small scan studies, a few parts of the cerebellum had slightly less gray matter. The cerebellum is a newer area of autism research. Evidence: Early. Stoodley, 2014
The whole brain and body (tends to be connected differently): Across the brain, studies report some links as stronger and some as weaker, and which it is depends on age and on the study. A multi-site analysis found a repeatable pattern, but autistic and non-autistic groups overlapped a lot, and the authors say it cannot be used to diagnose. Evidence: Moderate. Hull et al., 2017 (connectivity); Holiga et al., 2019

What tends to help:

Turn the load down: a quieter corner, headphones, dimmer lights, fewer surprises. Evidence: Early. Pfeiffer et al., 2019
Say what is coming: plans in writing, changes announced early. Not knowing what happens next is strongly tied to anxiety in autistic people, which is why many find this helps. That link is solid, but the help itself has not been tested much. Evidence: Early. Jenkinson et al., 2020
Plan recovery time after social effort, and treat it as needed, not as rude. Evidence: Early. Raymaker et al., 2020; Hull et al., 2017 (camouflaging)
Time with other autistic people, where communication tends to go smoothly. Evidence: Moderate. Crompton et al., 2020
Support for anxiety and low mood when they show up, since both are common. About one in four autistic adults had an anxiety disorder at the time of study in one pooled analysis. Evidence: Moderate. Hollocks et al., 2019

ADHD wiring

A neurodevelopmental difference. ADHD is often described as attention that is hard to aim and easy to lock on to, more than a plain shortage of it. Scan studies find small average differences in several deep regions, mostly seen in children, and in the networks that steer attention.

Basal ganglia (striatum) (tends to be smaller or thinner): The nucleus accumbens, caudate and putamen were slightly smaller on average, by about 0.1 to 0.15 of a standard deviation, in 1,713 people with ADHD and 1,529 without (ages 4 to 63, median 14). The gap was clearest in children and was smaller in adults, so this is not a finding about every age. Evidence: Strong. Hoogman et al., 2017
Amygdala (tends to be smaller or thinner): Slightly smaller on average, by about 0.2 of a standard deviation, the largest of the deep-region differences in that study, again mainly in children. Evidence: Strong. Hoogman et al., 2017
Hippocampus (tends to be smaller or thinner): Slightly smaller on average, by about a tenth of a standard deviation, mainly in children. Evidence: Strong. Hoogman et al., 2017
Amygdala (tends to be connected differently): Feelings that rise fast and are hard to bring back down are common in ADHD. Researchers propose a network linking the striatum, the amygdala and the middle of the prefrontal cortex. Evidence: Early. Shaw et al., 2014
Prefrontal cortex (tends to be less active): During attention and control tasks, front-of-brain regions in the control network were on average less active. Across 55 studies the pattern held even in people with no other condition and no history of stimulant use. Evidence: Moderate. Cortese et al., 2012
Sensory cortices (tends to be more active): Areas for movement were on average more active during tasks in children, and areas for seeing in adults. Evidence: Moderate. Cortese et al., 2012
Cerebellum (tends to be smaller or thinner): A small part of the cerebellum had slightly less gray matter in a pooled analysis of 10 scan studies. Evidence: Early. Stoodley, 2014
Frontoparietal control network (tends to be less active): The frontoparietal control network was on average less active in tasks that need steering. Evidence: Moderate. Cortese et al., 2012
Default mode network (tends to be more active): The default mode network was on average more active during tasks, when it usually quiets down. Evidence: Moderate. Cortese et al., 2012
The whole brain and body: In children, the cortex shows small average differences in surface area and thickness. The same study found no such differences in adolescents or adults. In a population sample of children, cortex measures also related, more weakly, to attention problems, which fits ADHD being the far end of a continuum. Evidence: Strong. Hoogman et al., 2019

What tends to help:

Medicine eases core symptoms for many people in the short term. Some choose it and some do not. Long-term evidence is thinner. Evidence: Strong. Cortese et al., 2018
Exercise, especially aerobic exercise, helped attention and hyperactivity in small trials with children. Evidence: Moderate. Cerrillo-Urbina et al., 2015
Put the task where you can see it: sticky notes, timers, a visible checklist, a first step that takes two minutes. Evidence: Early.
Work alongside someone, in the same room or on a call, even when you are doing different things. Evidence: Early.
Expect big feelings that pass fast, and agree on a pause line ahead of time. Evidence: Early. Shaw et al., 2014

Anxiety

A health condition that can improve. In anxiety, the body’s alarm tends to go off quickly and settle slowly. In social anxiety, phobias and PTSD, brain studies find that the alarm and body-signal regions react more strongly to threat on average. Generalized anxiety and panic are less well covered, and a small study found these regions change with treatment.

Amygdala (tends to be more active): More active than in comparison groups when people with social anxiety, a phobia or PTSD handle feared or emotional material. This is a reaction to cues, not constant activity. Evidence: Moderate. Etkin and Wager, 2007; Shin and Liberzon, 2010
Insula (tends to be more active): More active in the same studies. The insula reads the body (a racing heart, a tight stomach) and helps turn it into a feeling. Evidence: Moderate. Etkin and Wager, 2007; Shin and Liberzon, 2010
Prefrontal cortex (tends to be more variable): The front-of-brain areas that help settle the alarm show mixed results across anxiety conditions, so this one is marked early. Evidence: Early. Shin and Liberzon, 2010
Salience network (tends to be more active): The salience network, which pulls together the insula, the cingulate and the amygdala, is described as more reactive in anxiety, so more things get flagged as mattering. Evidence: Moderate. Etkin and Wager, 2007; Menon, 2011

What tends to help:

Cognitive behavioral therapy has the strongest support for anxiety problems, across many reviews. Evidence: Strong. Hofmann et al., 2012; NICE 2011; NICE 2013
Facing a feared thing in small steps, until your body learns it was safe enough, is a core part of that treatment. Evidence: Moderate. Craske et al., 2014
Regular movement lowers symptoms of anxiety, with medium-sized effects across many trials. Evidence: Strong. Singh et al., 2023
Put the feeling into words. Naming it lowered the alarm response in a lab task. Evidence: Moderate. Lieberman et al., 2007
Sleep. After a night without it, the amygdala reacted more strongly in one small study. Evidence: Moderate. Yoo et al., 2007
The brain changes with treatment. After nine weeks of internet-delivered therapy, the amygdala’s response and size both fell in a small trial. Evidence: Early. Månsson et al., 2016

Depression

A health condition that can improve. Depression changes mood, energy and interest, often for weeks or longer. Brain studies find small average differences in memory, mood and reward regions, clearer in people who have had repeated episodes.

Hippocampus (tends to be smaller or thinner): Slightly smaller on average, by about 1 percent, in 1,728 people with depression and 7,199 without. The gap was clearest in people with repeated episodes or an early start, and not seen in a first episode. Evidence: Strong. Schmaal et al., 2016
Prefrontal cortex (tends to be smaller or thinner): The orbitofrontal cortex, at the front above the eyes, was slightly thinner on average in adults, by about a tenth of a standard deviation. Evidence: Strong. Schmaal et al., 2017
Anterior cingulate cortex (tends to be smaller or thinner): The anterior cingulate was slightly thinner on average in adults, by about a tenth of a standard deviation. Evidence: Strong. Schmaal et al., 2017
Insula (tends to be smaller or thinner): The insula was slightly thinner on average in adults, by about a tenth of a standard deviation. Evidence: Strong. Schmaal et al., 2017
Amygdala (tends to be more active): More active on average when handling negative material, in pooled studies. Evidence: Moderate. Hamilton et al., 2012
Insula (tends to be more active): More active on average with negative material, in the same studies. Evidence: Moderate. Hamilton et al., 2012
Anterior cingulate cortex (tends to be more active): The dorsal part was more active on average with negative material. Evidence: Moderate. Hamilton et al., 2012
Prefrontal cortex (tends to be less active): The dorsolateral prefrontal cortex was less active on average in the same studies. Evidence: Moderate. Hamilton et al., 2012
Basal ganglia (striatum) (tends to be less active): The dorsal striatum was less active on average in the same studies. It is part of the reward and motivation circuitry. Evidence: Moderate. Hamilton et al., 2012
Frontoparietal control network (tends to be connected differently): Less connectivity inside the frontoparietal control network, and between it and the network that points attention outward. The differences are modest and the groups overlap. Evidence: Moderate. Kaiser et al., 2015

What tends to help:

Talking therapies, including cognitive behavioral therapy, and antidepressants, chosen together with a clinician, are the standard options. Evidence: Strong. NICE 2022
Behavioral activation: plan small things that matter to you and do them, before the energy shows up. Evidence: Moderate. Ekers et al., 2014
Regular movement lowers symptoms of depression, with medium-sized effects across many trials. Evidence: Strong. Singh et al., 2023
Mindfulness-based cognitive therapy cut the chance of relapse for people with repeated episodes. Evidence: Strong. Kuyken et al., 2016
Staying in touch with groups and people. Among people already depressed, joining a group was linked to lower risk of relapse. Evidence: Moderate. Cruwys et al., 2013

Trauma and PTSD

A health condition that can improve. After overwhelming events, the body’s alarm can stay switched on, and the past can feel present. Some of the studies here compare people with PTSD to people who also went through trauma but did not develop it, which is the fairest comparison. Others compare with people who were not exposed, so the comparison group differs from line to line.

Hippocampus (tends to be smaller or thinner): Slightly smaller on average, by about 0.17 of a standard deviation, in 1,868 people, compared with people who also lived through trauma but did not develop PTSD. A scan cannot show whether it was that way before. Evidence: Strong. Logue et al., 2018
Amygdala (tends to be more active): More active on average to trauma reminders and emotional material. Its size, by contrast, was not clearly different once the many regions tested were accounted for. Evidence: Moderate. Etkin and Wager, 2007; Hayes et al., 2012
Insula (tends to be more active): More active on average in the same studies. Evidence: Moderate. Etkin and Wager, 2007; Shin and Liberzon, 2010
Prefrontal cortex (tends to be less active): The ventromedial prefrontal cortex, which helps settle the alarm, was less active on average. Evidence: Moderate. Etkin and Wager, 2007; Hayes et al., 2012
Anterior cingulate cortex (tends to be more variable): Results differ by study and by part: some pooled studies find parts of the cingulate more active, others less. Evidence: Early. Etkin and Wager, 2007; Hayes et al., 2012
Salience network (tends to be more active): The salience network, which pulls together the insula, the cingulate and the amygdala, tends to react more to reminders of the trauma. Evidence: Moderate. Etkin and Wager, 2007; Shin and Liberzon, 2010
The whole brain and body: Beyond the brain, the heart beat faster on average at rest, during startle tests and when reminded of the trauma, in a pooled analysis of studies mostly of male veterans. Evidence: Moderate. Pole, 2007

What tends to help:

Trauma-focused cognitive behavioral therapy, and EMDR for adults more than three months after a non-combat trauma, are the recommended treatments. Evidence: Strong. NICE 2018
Predictable routines, a say in what happens next, and warning before touch or sudden changes. Evidence: Early.
Grounding with the senses: name five things you can see, feel your feet on the floor. Evidence: Early.
Treating insomnia. In a large trial of students, better sleep improved other mental health symptoms too. It was not a trauma study, so this one is a reasonable bet, not a proven one. Evidence: Early. Freeman et al., 2017

OCD

A health condition that can improve. OCD pairs unwanted, sticky thoughts (obsessions) with actions or mental rituals (compulsions) done to ease the distress. Studies point to loops that link the front of the brain with deep habit regions and the thalamus.

Basal ganglia (striatum) (tends to be larger or thicker): The pallidum, part of the basal ganglia, was slightly larger on average in adults (about 0.16 of a standard deviation), more so in people taking medicine. Evidence: Strong. Boedhoe et al., 2017
Hippocampus (tends to be smaller or thinner): Slightly smaller on average in adults, by about 0.13 of a standard deviation. Evidence: Strong. Boedhoe et al., 2017
Thalamus (tends to be larger or thicker): In children who were not taking medicine, the thalamus was larger on average (about 0.38 of a standard deviation, the largest effect in this set). Not seen in adults. Evidence: Strong. Boedhoe et al., 2017
Temporal-parietal areas (tends to be smaller or thinner): The inferior parietal cortex was slightly thinner on average, in both adults and children (effects of about 0.1 to 0.3 of a standard deviation). Evidence: Strong. Boedhoe et al., 2018
Habit loop (cortex, striatum, thalamus) (tends to be connected differently): Loops linking the front of the brain, the striatum and the thalamus work differently on average. Reviews say the circuit picture is wider than one loop. Evidence: Moderate. Milad and Rauch, 2012; Menzies et al., 2008
Anterior cingulate cortex (tends to be connected differently): The dorsal cingulate and the orbitofrontal cortex are implicated in reviews, but the direction depends on the study and the task. Evidence: Early. Milad and Rauch, 2012
Amygdala (tends to be connected differently): Circuits through the amygdala may matter too, including learning that a fear is no longer needed (called extinction). Evidence: Early. Milad and Rauch, 2012

What tends to help:

Cognitive behavioral therapy built on exposure and response prevention: facing the trigger and not doing the ritual. It cut symptoms a lot across 16 randomized trials. Evidence: Strong. Olatunji et al., 2013
Name it: “That’s the OCD talking.” Treat the thought as noise, not as news. Evidence: Early.
Family and friends: agree a plan to ease back on reassurance and on joining rituals, together, step by step. Evidence: Early.

Dyslexia

A neurodevelopmental difference. Dyslexia often comes from difficulty linking the sounds of speech to written letters. Brain studies find that the left-side reading network is on average less active during reading, and that good teaching changes both reading and the brain’s response.

Temporal-parietal areas (tends to be less active): During reading tasks, the left temporal-parietal areas and the lower back of the left side, where letter shapes are recognized, were on average less active, across 17 studies. This fits the difficulty linking letters to sounds. Evidence: Moderate. Richlan et al., 2009; Gabrieli, 2009
Prefrontal cortex (tends to be less active): The left inferior frontal gyrus, at the front left and linked to speech sounds, was less active on average in the same pooled studies. Evidence: Moderate. Richlan et al., 2009
Insula (tends to be more active): The anterior insula and the motor cortex were more active on average, which may be a way of working around the difficulty. Evidence: Moderate. Richlan et al., 2009
Cerebellum (tends to be smaller or thinner): A small part of the left cerebellum had slightly less gray matter in a pooled analysis of 10 scan studies. Evidence: Early. Stoodley, 2014
Reading network (tends to be less active): The reading network as a whole tends to be less active during reading. Evidence: Moderate. Richlan et al., 2009; Gabrieli, 2009

What tends to help:

Structured, phonics-based teaching, which builds explicit links between sounds and letters, was the one approach with a clearly confirmed benefit in 22 randomized trials. Evidence: Moderate. Galuschka et al., 2014
Teaching changes the brain’s response. In a small study of 20 children, activity in the left reading areas rose after a language and listening program. Evidence: Early. Temple et al., 2003; Gabrieli, 2009
Tools that take reading off the critical path: audiobooks, read-aloud tools, extra time, voice notes. Evidence: Early.
Praise ideas and effort, not spelling. Evidence: Early.

No label

A reference point, not a goal. This is the comparison point on the map, not a goal. Everyone sits somewhere on every slider, and the middle is a crowd, not a person. All ten regions do the same jobs in every brain.

The whole brain and body: No label does not mean no variation. After a night without sleep, the amygdala reacted more strongly to negative pictures in one small study, so even the same brain varies from day to day. Evidence: Moderate. Yoo et al., 2007
The whole brain and body: Experience shapes the brain. The back part of the hippocampus was larger on average in London taxi drivers, and larger the longer they had driven. Evidence: Moderate. Maguire et al., 2000

What tends to help:

Enough sleep. A night without it changed how strongly the amygdala reacted. Evidence: Moderate. Yoo et al., 2007
Regular movement lowers symptoms of depression, anxiety and distress, across many trials. Evidence: Strong. Singh et al., 2023
Staying connected to groups and people. Evidence: Moderate. Cruwys et al., 2013

Sources: where this comes from

Every finding on the map comes from one of the studies below, and each one is also listed, with a plain-words summary, on the research page. The links open the paper or its record in a new tab. The labels mean: Strong, replicated in large pooled studies; Moderate, pooled analyses or several consistent studies that are smaller, older or depend on the task; Early, a few small studies, one data set, or mostly expert reviews.

See them on the research page

Ben-Sasson, A., Hen, L., Fluss, R., et al. (2009)A meta-analysis of sensory modulation symptoms in individuals with autism spectrum disordersJournal of Autism and Developmental Disorders, 39(1), 1–11
Pooling 14 studies, autistic people reported or showed more sensory differences than comparison groups. The gap was largest for under-responding to sensations, then over-responding, then seeking sensations. The differences were largest in children aged 6 to 9.
Evidence: Strong A pooled analysis, backed by an update and by later reviews. Most studies relied on parent or self report.
Read more → doi.org/10.1007/s10803-008-0593-3
Boedhoe, P. S. W., Schmaal, L., Abe, Y., et al. (2017)Distinct subcortical volume alterations in pediatric and adult OCD: a worldwide meta- and mega-analysisAmerican Journal of Psychiatry, 174(1), 60–69
Pooling scans from 1,830 people with OCD and 1,759 comparison people, adults with OCD had slightly smaller hippocampi and slightly larger pallidums on average (about 0.13 and 0.16 of a standard deviation), while children with OCD who were not taking medicine had larger thalamus volumes (about 0.38). The adult and child patterns differed.
Evidence: Strong A large pooled analysis. The effects are small to moderate and the groups overlap a great deal; medicine use affected the results.
Read more → doi.org/10.1176/appi.ajp.2016.16020201
Boedhoe, P. S. W., Schmaal, L., Abe, Y., et al. (2018)Cortical abnormalities associated with pediatric and adult obsessive-compulsive disorder: findings from the ENIGMA Obsessive-Compulsive Disorder working groupAmerican Journal of Psychiatry, 175(5), 453–462
In scans of 1,905 people with OCD and 1,760 comparison people from 27 sites, the inferior parietal cortex was slightly thinner in both adults and children with OCD. Adults also showed a smaller surface area in one part of the temporal cortex. Effect sizes ranged from about 0.1 to 0.3 of a standard deviation.
Evidence: Strong A large pooled analysis. The effects are small and medicine use affected some results.
Read more → doi.org/10.1176/appi.ajp.2017.17050485
Cerrillo-Urbina, A. J., García-Hermoso, A., Sánchez-López, M., Pardo-Guijarro, M. J., Santos Gómez, J. L., & Martínez-Vizcaíno, V. (2015)The effects of physical exercise in children with attention deficit hyperactivity disorder: a systematic review and meta-analysis of randomized control trialsChild: Care, Health and Development, 41(6), 779–788
Across eight small trials (249 children with ADHD), exercise, especially aerobic exercise, improved attention, hyperactivity and related symptoms compared with control groups.
Evidence: Moderate A meta-analysis of small randomized trials.
Read more → doi.org/10.1111/cch.12255
Cortese, S., Kelly, C., Chabernaud, C., et al. (2012)Toward systems neuroscience of ADHD: a meta-analysis of 55 fMRI studiesAmerican Journal of Psychiatry, 169(10), 1038–1055
Pooling 55 brain-activity studies, people with ADHD showed on average less activation in the frontoparietal (control) and ventral attention networks, and more activation in the default network and some sensory and motor areas, than comparison people. The differences were seen even without other conditions or past stimulant use.
Evidence: Moderate A pooled analysis of 55 mostly small studies. Task choice matters, and the groups overlap a great deal.
Read more → doi.org/10.1176/appi.ajp.2012.11101521
Cortese, S., Adamo, N., Del Giovane, C., et al. (2018)Comparative efficacy and tolerability of medications for attention-deficit hyperactivity disorder in children, adolescents, and adults: a systematic review and network meta-analysisThe Lancet Psychiatry, 5(9), 727–738
Pooling 133 double-blind trials, medicines for ADHD reduced core symptoms in the short term. Taking both benefit and side effects into account, methylphenidate (for children and teenagers) and amphetamines (for adults) came out as the preferred first choices. The authors called for studies of long-term effects.
Evidence: Strong A large analysis of 133 randomized trials, but short-term, and the long-term evidence is thin.
Read more → doi.org/10.1016/S2215-0366(18)30269-4
Craske, M. G., Treanor, M., Conway, C. C., Zbozinek, T., & Vervliet, B. (2014)Maximizing exposure therapy: An inhibitory learning approachBehaviour Research and Therapy, 58, 10–23
Describes exposure therapy for anxiety as building new learning that competes with old fear, and sets out ways to strengthen it, such as testing specific expectations, dropping safety behaviors and practicing in varied settings.
Evidence: Moderate Theory-led clinical review drawing on lab and treatment research
Read more → doi.org/10.1016/j.brat.2014.04.006
Crompton, C. J., Ropar, D., Evans-Williams, C. V. M., Flynn, E. G., & Fletcher-Watson, S. (2020)Autistic peer-to-peer information transfer is highly effectiveAutism, 24(7), 1704–1712
In "diffusion chains" where a story was passed along eight people (72 adults), all-autistic chains passed on as much detail as all-non-autistic chains, while mixed chains lost detail faster and reported lower rapport.
Evidence: Moderate A careful experiment that supports the double empathy idea. Modest sample and a single task.
Read more → doi.org/10.1177/1362361320919286
Cruwys, T., Dingle, G. A., Haslam, C., Haslam, S. A., Jetten, J., & Morton, T. A. (2013)Social group memberships protect against future depression, alleviate depression symptoms and prevent depression relapseSocial Science & Medicine, 98, 179–186
In population data on adults aged 50 and over followed for two to four years, belonging to fewer groups predicted more depression later. Among people already depressed, joining one group was linked to a 24% lower risk of relapse and joining three to a 63% lower risk.
Evidence: Moderate Large longitudinal samples, but observational, so links rather than proof
Read more → doi.org/10.1016/j.socscimed.2013.09.013
Demetriou, E. A., Lampit, A., Quintana, D. S., et al. (2018)Autism spectrum disorders: A meta-analysis of executive functionMolecular Psychiatry, 23, 1198–1204
Pooling 235 studies with over 14,000 participants, found that autistic people on average scored lower than non-autistic people across executive function tasks, with wide variation and mixed findings across ages.
Evidence: Moderate Large meta-analysis of lab tasks, which capture only part of daily life
Read more → doi.org/10.1038/mp.2017.75
Ekers, D., Webster, L., Van Straten, A., Cuijpers, P., Richards, D., & Gilbody, S. (2014)Behavioural activation for depression; an update of meta-analysis of effectiveness and sub group analysisPLoS ONE, 9(6), e100100
Across 26 randomized trials (1,524 people), behavioral activation, planning and doing small valued activities, reduced depression more than control conditions, and at least as much as medication in the four trials that compared them.
Evidence: Moderate Consistent effects, but most studies were small or low quality with short follow-up
Read more → doi.org/10.1371/journal.pone.0100100
Etkin, A., & Wager, T. D. (2007)Functional neuroimaging of anxiety: a meta-analysis of emotional processing in PTSD, social anxiety disorder, and specific phobiaAmerican Journal of Psychiatry, 164(10), 1476–1488
Pooling brain-activity studies, people with PTSD, social anxiety disorder or a specific phobia showed, on average, more activity in the amygdala and the insula than comparison people while handling emotional material, similar to what happens in healthy people during fear learning. Only in PTSD were the front-of-brain areas that help settle feelings (parts of the cingulate and the ventromedial prefrontal cortex) less active.
Evidence: Moderate A pooled analysis of many small studies from before 2007. Later work generally agrees, but individual studies vary and the groups overlap.
Read more → doi.org/10.1176/appi.ajp.2007.07030504
Freeman, D., Sheaves, B., et al. (2017)The effects of improving sleep on mental health (OASIS): A randomised controlled trial with mediation analysisThe Lancet Psychiatry, 4(10), 749–758
In 3,755 university students with insomnia, an online CBT course for sleep greatly reduced insomnia and also reduced paranoid thoughts and hallucinatory experiences compared with usual care, with better sleep explaining much of the change.
Evidence: Strong Very large randomized trial. Students only, so results may not apply to everyone
Read more → doi.org/10.1016/S2215-0366(17)30328-0
Gabrieli, J. D. E. (2009)Dyslexia: a new synergy between education and cognitive neuroscienceScience, 325(5938), 280–283
A review explaining that dyslexia often comes from difficulty linking the sounds of speech to letters, that brain studies of children with dyslexia show less engagement of the left temporoparietal cortex during reading, and that good teaching changes both reading and the brain's response. It argues that early, evidence-based teaching could prevent most reading failure.
Evidence: Moderate An influential expert review. The brain findings are averages with large overlap.
Read more → doi.org/10.1126/science.1171999
Galuschka, K., Ise, E., Krick, K., & Schulte-Körne, G. (2014)Effectiveness of treatment approaches for children and adolescents with reading disabilities: a meta-analysis of randomized controlled trialsPLoS ONE, 9(2), e89900
Pooling 22 randomized trials, teaching that builds explicit links between sounds and letters (phonics) was the one approach with a clearly confirmed benefit for reading and spelling in children and adolescents with reading difficulties. The authors concluded that even severe reading and spelling difficulties can be improved with the right teaching.
Evidence: Moderate 22 randomized trials, but many were small, and other approaches had fewer studies, so they are not proven not to work.
Read more → doi.org/10.1371/journal.pone.0089900
Grove, R., Hoekstra, R. A., Wierda, M., & Begeer, S. (2018)Special interests and subjective wellbeing in autistic adultsAutism Research, 11(5), 766–775
In a survey of autistic adults in the Netherlands Autism Register, about two-thirds reported a special interest. Greater motivation for the interest was linked to higher wellbeing, while very high intensity of engagement was linked to lower wellbeing.
Evidence: Moderate Large survey, cross-sectional and self-report
Read more → research.vu.nl
Hamilton, J. P., Etkin, A., Furman, D. J., et al. (2012)Functional neuroimaging of major depressive disorder: a meta-analysis and new integration of baseline activation and neural response dataAmerican Journal of Psychiatry, 169(7), 693–703
In response to negative material, people with depression showed on average more activity in the amygdala, insula and dorsal anterior cingulate cortex, and less in the dorsal striatum and dorsolateral prefrontal cortex, than comparison people.
Evidence: Moderate A pooled analysis of many small studies; results depend on the task, and the groups overlap.
Read more → doi.org/10.1176/appi.ajp.2012.11071105
Hayes, J. P., Hayes, S. M., & Mikedis, A. M. (2012)Quantitative meta-analysis of neural activity in posttraumatic stress disorderBiology of Mood & Anxiety Disorders, 2, 9
Pooling 26 brain-activity studies, people with PTSD showed more activity on average in the middle and dorsal anterior cingulate and (when region-of-interest studies were included) the amygdala, and less activity in the ventromedial prefrontal cortex and the inferior frontal gyrus than comparison people.
Evidence: Moderate A pooled analysis of 26 studies. Results depend on the task and on which comparison group was used, and the groups overlap.
Read more → doi.org/10.1186/2045-5380-2-9
Hofmann, S. G., Asnaani, A., Vonk, I. J. J., Sawyer, A. T., & Fang, A. (2012)The efficacy of cognitive behavioral therapy: A review of meta-analysesCognitive Therapy and Research, 36(5), 427–440
Reviewing 106 meta-analyses of cognitive behavioral therapy, found the strongest support for anxiety problems, bulimia, anger and general stress, with support across many other problems. Few studies looked at groups such as ethnic minorities or people on low incomes.
Evidence: Strong A review of many meta-analyses. Quality of the underlying trials varies
Read more → doi.org/10.1007/s10608-012-9476-1
Holiga, Š., Hipp, J. F., Chatham, C. H., et al. (2019)Patients with autism spectrum disorders display reproducible functional connectivity alterationsScience Translational Medicine, 11(481), eaat9223
In several large data sets, autistic people showed a reproducible pattern of differences in how brain regions work together. The pattern was only moderately linked to day-to-day traits and overlapped a lot with comparison people, so the authors say it is not usable for diagnosis.
Evidence: Moderate Replicated across several data sets, with a large overlap between groups.
Read more → doi.org/10.1126/scitranslmed.aat9223
Hollocks, M. J., Lerh, J. W., Magiati, I., Meiser-Stedman, R., & Brugha, T. S. (2019)Anxiety and depression in adults with autism spectrum disorder: A systematic review and meta-analysisPsychological Medicine, 49(4), 559–572
Pooling 35 studies, estimated that about 27% of autistic adults had an anxiety disorder at the time (42% over their lifetime) and about 23% had depression (37% lifetime), with wide variation between studies.
Evidence: Moderate Meta-analysis. Very varied methods and many clinical samples
Read more → doi.org/10.1017/S0033291718002283
Hoogman, M., Bralten, J., Hibar, D. P., et al. (2017)Subcortical brain volume differences in participants with attention deficit hyperactivity disorder in children and adults: a cross-sectional mega-analysisThe Lancet Psychiatry, 4(4), 310–319
In 1,713 people with ADHD and 1,529 comparison people at 23 sites (ages 4 to 63, median 14), the nucleus accumbens, amygdala, caudate, hippocampus and putamen were slightly smaller on average in the ADHD group (very small effects, about 0.1 to 0.2 of a standard deviation). The differences were clearest in children and smaller in adults. The pallidum and thalamus did not differ.
Evidence: Strong A very large pooled scan study. The effects are very small and the groups overlap almost completely.
Read more → doi.org/10.1016/S2215-0366(17)30049-4
Hoogman, M., Muetzel, R., Guimaraes, J. P., et al. (2019)Brain imaging of the cortex in ADHD: a coordinated analysis of large-scale clinical and population-based samplesAmerican Journal of Psychiatry, 176(7), 531–542
Comparing the cortex of 2,246 people with ADHD and 1,934 comparison people from 36 centers, the authors found small average differences in cortical surface area in children, with some thickness differences. They found no differences in thickness or surface area in adolescents or adults. In a population sample of children, surface area also related, more weakly, to attention problems, which fits the view that ADHD sits at one end of a continuum.
Evidence: Strong A large coordinated analysis. The differences are small and were found in children, not in adolescents or adults.
Read more → doi.org/10.1176/appi.ajp.2019.18091033
Hull, L., Petrides, K. V., Allison, C., Smith, P., Baron-Cohen, S., Lai, M.-C., & Mandy, W. (2017)"Putting on my best normal": Social camouflaging in adults with autism spectrum conditionsJournal of Autism and Developmental Disorders, 47(8), 2519–2534
Interviews with 92 autistic adults described camouflaging as motivated by wanting to fit in and connect, done through masking and compensating techniques, and often followed by exhaustion and threats to self-perception.
Evidence: Moderate A qualitative study that shaped later measurement work.
Read more → doi.org/10.1007/s10803-017-3166-5
Hull, J. V., Jacokes, Z. J., Torgerson, C. M., Irimia, A., & Van Horn, J. D. (2017)Resting-state functional connectivity in autism spectrum disorders: a reviewFrontiers in Psychiatry, 7, 205
A review of brain-connectivity studies in autism. Studies have reported more connectivity, less connectivity, or a mix, and the authors link the differences between studies to age, sex, scan design and the wide variation among autistic people.
Evidence: Moderate A review whose main message is that results are mixed.
Read more → doi.org/10.3389/fpsyt.2016.00205
Jenkinson, R., Milne, E., & Thompson, A. (2020)The relationship between intolerance of uncertainty and anxiety in autism: A systematic literature review and meta-analysisAutism, 24(8), 1933–1944
Across 10 studies pooled in a meta-analysis (12 reviewed), finding uncertainty hard to bear was strongly linked with anxiety in autistic people (r = 0.62), a link of similar size to that found in non-autistic people.
Evidence: Moderate A meta-analysis, but of a small number of studies with methodological concerns. Correlational
Read more → doi.org/10.1177/1362361320932437
Kaiser, R. H., Andrews-Hanna, J. R., Wager, T. D., & Pizzagalli, D. A. (2015)Large-scale network dysfunction in major depressive disorder: a meta-analysis of resting-state functional connectivityJAMA Psychiatry, 72(6), 603–611
Pooling 27 data sets (556 people with depression and 518 comparison people), depression was linked on average to less connectivity within the frontoparietal control network and between it and a network that directs attention to the outside world.
Evidence: Moderate A pooled analysis of mostly small studies; the differences are modest and the groups overlap.
Read more → doi.org/10.1001/jamapsychiatry.2015.0071
Kuyken, W., et al. (2016)Efficacy of mindfulness-based cognitive therapy in prevention of depressive relapse: an individual patient data meta-analysis from randomized trialsJAMA Psychiatry, 73(6), 565–574
Across nine trials (1,258 people with recurrent depression), mindfulness-based cognitive therapy cut the risk of relapse over 60 weeks by about 31% (38% relapsed versus 49%).
Evidence: Strong An individual-patient meta-analysis of randomized trials.
Read more → doi.org/10.1001/jamapsychiatry.2016.0076
Lieberman, M. D., Eisenberger, N. I., Crockett, M. J., Tom, S. M., Pfeifer, J. H., & Way, B. M. (2007)Putting feelings into words: Affect labeling disrupts amygdala activity in response to affective stimuliPsychological Science, 18(5), 421–428
In a brain-imaging study, labeling the emotion in a picture reduced amygdala and other limbic responses compared with other ways of processing the image.
Evidence: Moderate Replicated lab finding. Effects are modest and mostly measured with pictures in the lab.
Read more → doi.org/10.1111/j.1467-9280.2007.01916.x
Logue, M. W., van Rooij, S. J. H., Dennis, E. L., et al. (2018)Smaller hippocampal volume in posttraumatic stress disorder: a multisite ENIGMA-PGC studyBiological Psychiatry, 83(3), 244–253
Across 16 groups of researchers and 1,868 people, those with current PTSD had slightly smaller hippocampi on average than trauma-exposed people without PTSD (a small effect, about 0.17 of a standard deviation). The amygdala difference was smaller still and did not hold up after correcting for the number of regions tested.
Evidence: Strong A large pooled analysis with a fair comparison group (people who had also been through trauma). The effect is small and a scan study cannot say whether it was there before the trauma.
Read more → doi.org/10.1016/j.biopsych.2017.09.006
Maguire, E. A., Gadian, D. G., Johnsrude, I. S., et al. (2000)Navigation-related structural change in the hippocampi of taxi driversProceedings of the National Academy of Sciences, 97(8), 4398–4403
The back part of the hippocampus was larger on average in London taxi drivers than in comparison people, and it was larger the longer someone had driven a taxi, which suggests the adult brain changes with long experience.
Evidence: Moderate A classic study with many follow-ups on brain change. It links experience and size and cannot prove one caused the other.
Read more → doi.org/10.1073/pnas.070039597
Månsson, K. N. T., Salami, A., Frick, A., et al. (2016)Neuroplasticity in response to cognitive behavior therapy for social anxiety disorderTranslational Psychiatry, 6, e727
In 26 people with social anxiety disorder who had nine weeks of internet-delivered cognitive behavioral therapy, the amygdala's volume and its response to criticism both fell on average, and the drop in volume tracked the drop in anxiety. A comparison treatment did not show the same changes.
Evidence: Early One small trial, though it shows that the brain responds to effective treatment.
Read more → doi.org/10.1038/tp.2015.218
Menon, V. (2011)Large-scale brain networks and psychopathology: a unifying triple network modelTrends in Cognitive Sciences, 15(10), 483–506
Proposed that problems in how three large networks switch on and off, the salience, frontoparietal and default networks, show up across many conditions, with the salience network acting as a switch between the other two.
Evidence: Moderate An influential model that has guided much research. It is a framework to test, not a settled finding.
Read more → doi.org/10.1016/j.tics.2011.08.003
Menzies, L., Chamberlain, S. R., Laird, A. R., et al. (2008)Integrating evidence from neuroimaging and neuropsychological studies of obsessive-compulsive disorder: the orbitofronto-striatal model revisitedNeuroscience & Biobehavioral Reviews, 32(3), 525–549
A review and pooled analysis of brain-imaging studies of OCD. It tests the long-standing idea of an orbitofrontal-striatal loop and proposes a wider picture that includes other areas, including parts of the parietal cortex.
Evidence: Moderate An expert review and pooled analysis from before the large scan studies.
Read more → doi.org/10.1016/j.neubiorev.2007.09.005
Milad, M. R., & Rauch, S. L. (2012)Obsessive-compulsive disorder: beyond segregated cortico-striatal pathwaysTrends in Cognitive Sciences, 16(1), 43–51
A review arguing that OCD involves more than the loops linking the front of the brain, the striatum and the thalamus: the orbitofrontal cortex, the dorsal anterior cingulate and circuits through the amygdala also matter, and learning that a fear is no longer needed (extinction) may work differently.
Evidence: Moderate An expert review of imaging and treatment studies. It describes circuits that appear involved, and cannot say what causes what.
Read more → doi.org/10.1016/j.tics.2011.11.003
Milton, D. E. M. (2012)On the ontological status of autism: The “double empathy problem”Disability & Society, 27(6), 883–887
A short conceptual paper arguing that misunderstanding between autistic and non-autistic people runs both ways: each side finds the other hard to read, so the problem lies between them, not only in the autistic person.
Evidence: Early A conceptual paper, not a test of one. no data in the paper itself. Later experiments (e.g. Crompton and colleagues, 2020) support parts of it
Read more → autism.org.uk
Murray, D., Lesser, M., & Lawson, W. (2005)Attention, monotropism and the diagnostic criteria for autismAutism, 9(2), 139–156
Proposed "monotropism": autistic attention tends to be pulled strongly into a few interests at a time, and the authors argued this can explain the other diagnostic features of autism.
Evidence: Early A conceptual paper, not a test of one. an influential, autistic-led account. Empirical testing is still limited.
Read more → doi.org/10.1177/1362361305051398
National Institute for Health and Care Excellence (NICE) (2011)Generalised anxiety disorder and panic disorder in adults: management (CG113)NICE guideline (updated 2020)
Recommends stepped care: self-help first, then CBT or applied relaxation (or medicine) for generalized anxiety, and CBT for panic disorder.
Evidence: Strong A national guideline based on reviews of trials.
Read more → nice.org.uk
National Institute for Health and Care Excellence (NICE) (2013)Social anxiety disorder: recognition, assessment and treatment (CG159)NICE guideline
Recommends individual CBT developed specifically for social anxiety for adults with social anxiety disorder.
Evidence: Strong A national guideline based on reviews of trials.
Read more → nice.org.uk
National Institute for Health and Care Excellence (NICE) (2018)Post-traumatic stress disorder (NG116)NICE guideline
Recommends trauma-focused CBT for adults with PTSD, and EMDR for adults with PTSD more than three months after a non-combat trauma.
Evidence: Strong A national guideline based on reviews of trials.
Read more → nice.org.uk
National Institute for Health and Care Excellence (NICE) (2022)Depression in adults: treatment and management (NG222)NICE guideline NG222, London
The national health guideline for England on depression: recommends a choice of treatments made together with the person, including guided self-help, group or individual CBT and behavioral activation, group exercise, other talking therapies and antidepressants.
Evidence: Strong An official guideline based on systematic reviews. Some methods have been criticized
Read more → nice.org.uk
Nolen-Hoeksema, S. (1991)Responses to depression and their effects on the duration of depressive episodesJournal of Abnormal Psychology, 100(4), 569–582
Proposed the response styles theory: people who ruminate on their low mood tend to have longer depressions than people who distract themselves.
Evidence: Strong Extensive, consistent later research.
Read more → doi.org/10.1037/0021-843X.100.4.569
Olatunji, B. O., Davis, M. L., Powers, M. B., & Smits, J. A. J. (2013)Cognitive-behavioral therapy for obsessive-compulsive disorder: a meta-analysis of treatment outcome and moderatorsJournal of Psychiatric Research, 47(1), 33–41
Pooling 16 randomized trials (756 people), cognitive behavioral therapy, centered on exposure and response prevention, reduced OCD symptoms much more than control conditions right after treatment, with a smaller but lasting benefit at follow-up.
Evidence: Strong Pooled randomized trials with a large effect. Follow-up results are smaller and the trials vary in quality.
Read more → doi.org/10.1016/j.jpsychires.2012.08.020
Panagiotidi, M., Overton, P. G., & Stafford, T. (2017)The relationship between ADHD traits and sensory sensitivity in the general populationComprehensive Psychiatry, 80, 179–185
In an online survey of 234 adults, more ADHD traits went with more reported sensory difficulties in every sense, suggesting sensory differences may be part of the ADHD picture.
Evidence: Early A single survey of adults from the general population, with self-report only.
Read more → eprints.whiterose.ac.uk
Pfeiffer, B., Stein Duker, L., Murphy, A., & Shui, C. (2019)Effectiveness of noise-attenuating headphones on physiological responses for children with autism spectrum disordersFrontiers in Integrative Neuroscience, 13, 65
In six autistic children, wearing noise-attenuating headphones during the day changed skin-conductance measures of stress compared with baseline.
Evidence: Early A single-subject design with six children.
Read more → doi.org/10.3389/fnint.2019.00065
Pole, N. (2007)The psychophysiology of posttraumatic stress disorder: a meta-analysisPsychological Bulletin, 133(5), 725–746
Pooling studies of the body's responses, adults with PTSD had a faster heart rate than adults without PTSD at rest, during startle tests and when reminded of the trauma. Heart rate was among the most consistent differences. Most studies were of male veterans.
Evidence: Moderate A pooled analysis of many studies, but one limited to the groups that were studied most.
Read more → doi.org/10.1037/0033-2909.133.5.725
Raymaker, D. M., Teo, A. R., Steckler, N. A., et al. (2020)"Having all of your internal resources exhausted beyond measure and being left with no clean-up crew": Defining autistic burnoutAutism in Adulthood, 2(2), 132–143
From 19 interviews and 19 public online accounts, analyzed with autistic co-researchers, autistic burnout was defined as long-term exhaustion, loss of function and reduced tolerance to stimulus, arising from chronic life stress and a mismatch between expectations and abilities without enough support.
Evidence: Early The first formal definition, from a qualitative community-based study. Distinct from occupational burnout and depression in participants' accounts.
Read more → doi.org/10.1089/aut.2019.0079
Richlan, F., Kronbichler, M., & Wimmer, H. (2009)Functional abnormalities in the dyslexic brain: a quantitative meta-analysis of neuroimaging studiesHuman Brain Mapping, 30(10), 3299–3308
Pooling 17 brain-activity studies of reading, people with dyslexia showed on average less activity in the left inferior parietal, superior temporal, middle and inferior temporal, and fusiform areas, and in the left inferior frontal gyrus, together with more activity in the primary motor cortex and anterior insula, which may be a way of working around the difficulty.
Evidence: Moderate A pooled analysis of 17 studies, with later reviews pointing the same way. Study sizes were small and the groups overlap.
Read more → doi.org/10.1002/hbm.20752
Robertson, C. E., & Baron-Cohen, S. (2017)Sensory perception in autismNature Reviews Neuroscience, 18(11), 671–684
A review arguing that sensory experience is a central part of autism, noting that unusual sensory experience may affect as many as nine in ten autistic people, across all the senses, and discussing what is known about how sensory processing works differently.
Evidence: Moderate An expert review. The explanations for why are still being tested.
Read more → doi.org/10.1038/nrn.2017.112
Sasson, N. J., Faso, D. J., Nugent, J., Lovell, S., Kennedy, D. P., & Grossman, R. B. (2017)Neurotypical peers are less willing to interact with those with autism based on thin slice judgmentsScientific Reports, 7, 40700
Across three studies, non-autistic observers formed less favorable first impressions of autistic children and adults from a few seconds of video, and were less willing to interact with them. The bias disappeared when they judged only transcripts of what was said.
Evidence: Moderate Three studies with consistent results. Suggests style, not substance, drives the bias.
Read more → doi.org/10.1038/srep40700
Schmaal, L., Veltman, D. J., van Erp, T. G. M., et al. (2016)Subcortical brain alterations in major depressive disorder: findings from the ENIGMA Major Depressive Disorder working groupMolecular Psychiatry, 21(6), 806–812
Pooling scans from 1,728 people with major depression and 7,199 comparison people at 15 sites, the hippocampus was smaller on average in the depression group (a very small effect, about 1 percent). The difference was clearest in people with repeated episodes and in those whose depression began before age 21, and not seen in people in their first episode.
Evidence: Strong One of the largest pooled scan studies of depression. The effect is small, the groups overlap almost completely, and a scan study cannot say which came first.
Read more → doi.org/10.1038/mp.2015.69
Schmaal, L., Hibar, D. P., Sämann, P. G., et al. (2017)Cortical abnormalities in adults and adolescents with major depression based on brain scans from 20 cohorts worldwide in the ENIGMA Major Depressive Disorder working groupMolecular Psychiatry, 22(6), 900–909
In scans of 2,148 people with major depression and 7,957 comparison people, adults with depression had slightly thinner cortex on average in the orbitofrontal cortex, the anterior and posterior cingulate, the insula and the temporal lobes (small effects, about 0.1 of a standard deviation). Adolescents showed a smaller total surface area instead.
Evidence: Strong A very large pooled scan study. The effects are small and the groups overlap almost completely.
Read more → doi.org/10.1038/mp.2016.60
Shaw, P., Stringaris, A., Nigg, J., & Leibenluft, E. (2014)Emotion dysregulation in attention deficit hyperactivity disorderAmerican Journal of Psychiatry, 171(3), 276-293
A literature review found that trouble regulating emotions (quick, strong feelings that are hard to bring back down) is common in ADHD across the lifespan, with clinic studies of young people putting it at roughly 25 to 50 percent, and that it adds a lot to the day-to-day difficulty ADHD brings.
Evidence: Moderate A widely cited review. The estimates come mostly from clinic samples, and how emotion dysregulation fits into ADHD is still debated.
Read more → doi.org/10.1176/appi.ajp.2013.13070966
Shin, L. M., & Liberzon, I. (2010)The neurocircuitry of fear, stress, and anxiety disordersNeuropsychopharmacology, 35(1), 169–191
A review of animal and human work on fear circuits. In PTSD, social anxiety and specific phobia the amygdala tends to respond more strongly to cues tied to the fear, and the insula is often more active across several anxiety disorders. In PTSD the rostral anterior cingulate and nearby ventromedial prefrontal cortex tend to respond less. The authors note it is not yet clear which differences come first.
Evidence: Moderate An expert review that agrees with the pooled analyses. It cannot say what causes what.
Read more → doi.org/10.1038/npp.2009.83
Singh, B., et al. (2023)Effectiveness of physical activity interventions for improving depression, anxiety and distress: an overview of systematic reviewsBritish Journal of Sports Medicine
An overview of 97 reviews (1,039 trials, about 128,000 people) found physical activity reduced symptoms of depression, anxiety and distress compared with usual care, with medium-sized effects.
Evidence: Strong A very large body of trials. The trials vary a lot in quality and type of exercise.
Read more → doi.org/10.1136/bjsports-2022-106195
Stoodley, C. J. (2014)Distinct regions of the cerebellum show gray matter decreases in autism, ADHD, and developmental dyslexiaFrontiers in Systems Neuroscience, 8, 92
Pooling scan studies of autism (17), ADHD (10) and dyslexia (10), no cerebellar area was larger in any group, and each condition had smaller gray matter in a different part of the cerebellum, with no overlap between conditions.
Evidence: Early A pooled analysis of mostly small scan studies; the sizes are modest and the groups overlap.
Read more → doi.org/10.3389/fnsys.2014.00092
Temple, E., Deutsch, G. K., Poldrack, R. A., et al. (2003)Neural deficits in children with dyslexia ameliorated by behavioral remediation: evidence from functional MRIProceedings of the National Academy of Sciences, 100(5), 2860–2865
In 20 children with dyslexia aged 8 to 12, a language and listening training program improved reading and language scores, and brain activity during sound-based tasks rose in the left temporoparietal cortex and left inferior frontal gyrus, moving closer to the pattern seen in typical readers.
Evidence: Early One small study with no matched untreated group of children with dyslexia. It shows the brain responds to teaching but cannot say how much.
Read more → doi.org/10.1073/pnas.0030098100
van Rooij, D., Anagnostou, E., Arango, C., et al. (2018)Cortical and subcortical brain morphometry differences between patients with autism spectrum disorder and healthy individuals across the lifespan: results from the ENIGMA ASD working groupAmerican Journal of Psychiatry, 175(4), 359–369
Scans of 1,571 autistic people and 1,651 comparison people (ages 2 to 64, 49 sites) showed small average differences: slightly smaller pallidum, putamen, amygdala and nucleus accumbens, slightly thicker frontal cortex and slightly thinner temporal cortex (effect sizes about 0.1 to 0.2 of a standard deviation). The differences in cortical thickness were largest around adolescence.
Evidence: Strong The largest scan study of autism to date. The effects are very small, the groups overlap almost completely, and autistic people differ widely from each other.
Read more → doi.org/10.1176/appi.ajp.2017.17010100
Woodward, N. D., Giraldo-Chica, M., Rogers, B., & Cascio, C. J. (2017)Thalamocortical dysconnectivity in autism spectrum disorder: an analysis of the Autism Brain Imaging Data ExchangeBiological Psychiatry: Cognitive Neuroscience and Neuroimaging, 2(1), 76–84
Comparing 228 autistic people with 228 matched comparison people, the thalamus was more strongly connected on average with prefrontal, temporal and sensory-motor cortex in the autism group, most clearly in adolescents. Other studies have found less connectivity in some thalamus pathways, so the direction is not settled.
Evidence: Early One data set, and other studies point in mixed directions.
Read more → pmc.ncbi.nlm.nih.gov
Yoo, S.-S., Gujar, N., Hu, P., Jolesz, F. A., & Walker, M. P. (2007)The human emotional brain without sleep—a prefrontal amygdala disconnectCurrent Biology, 17(20), R877–R878
After a night without sleep, the amygdala reacted more strongly to negative pictures and was less connected to the prefrontal cortex.
Evidence: Moderate A small lab study, consistent with later sleep research.
Read more → doi.org/10.1016/j.cub.2007.08.007

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Last updated: October 2026