Each page here takes one study, or one idea and the studies that tested it, and sets out
what was found, what it can’t tell you, and where we rely on it.
Foundational guide One idea, every study that tested it
Foundational paper: Barkley RA. Behavioral inhibition, sustained attention, and executive functions: constructing a unifying theory of ADHD. Psychological Bulletin 1997;121(1):65–94. doi:10.1037/0033-2909.121.1.65
Executive-function theories changed how ADHD was understood: less as a failure to know what to do, more as difficulty carrying an intention across time. The evidence supports meaningful differences in inhibition, working memory, planning, and shifting at the group level. It does not support one broken “executive system” that explains every person with ADHD.
5 key papers, annotated: Barkley 1997 · Diamond 2013 · Willcutt et al. 2005 · Boonstra et al. 2005 · Mostert et al. 2015.
One proposal, then a decade of tests. Each dot is a paper the guide annotates.
ADHD and autism are distinct diagnoses that often occur in the same person. Family, twin, trait-structure, registry, and health-record studies all support real overlap. They also show meaningful differences. “AuDHD” is useful community language for that intersection, not evidence that the two conditions collapse into one.
5 key papers: Rommelse et al. 2010 · Ghirardi et al. 2019 · Solberg et al. 2019 · Krakowski et al. 2021 · Yerys et al. 2025.
Autistic people and researchers describe burnout as a pattern of exhaustion, reduced functioning, withdrawal, and increased sensory strain after demands outrun support. Depression can overlap with that pattern, follow it, or occur alongside it. The research increasingly treats autistic burnout as a useful construct, but it does not yet provide a clinical test that can separate the two for one person.
5 key papers: Raymaker et al. 2020 · Higgins et al. 2021 · Mantzalas et al. 2022 · Arnold et al. 2023 · Bougoure et al. 2026.
In 2012 an autistic sociologist proposed that the misunderstanding between autistic and non-autistic people runs both ways. A decade of experiments has tested it. Here’s what held, what shifted, and what nobody has measured yet.
11 key papers: Milton 2012 · Sheppard et al. 2016 · Edey et al. 2016 · Sasson et al. 2017 · Heasman and Gillespie 2018 · Crompton et al. 2020 · Crompton et al. 2020 · Morrison et al. 2020 · Mitchell et al. 2021 · Davis and Crompton 2021 · Milton et al. 2022.
Kinnaird E, Stewart C, Tchanturia K. Investigating alexithymia in autism: a systematic review and meta-analysis. European Psychiatry 2019;55:80–89. doi:10.1016/j.eurpsy.2018.09.004Open full text
A meta-analysis of 15 studies found that autistic participants scored substantially higher on one common alexithymia questionnaire than non-autistic comparison groups. About half crossed the scale’s cut-off. That is evidence of frequent co-occurrence, not evidence that difficulty identifying feelings is part of every autistic person’s experience.
Design
Systematic review and random-effects meta-analysis of case-control studies
Sample
15 studies; 366 autistic participants and 348 non-autistic comparison participants
Where
International literature searched through January 2018
A 2011 review gathered brain-response studies of sound, touch, vision, and multisensory information in autistic people. It found repeated signs that sensory processing can differ—and repeated contradictions about where, when, and in whom. The paper made sensory experience harder to dismiss, but its proposed brain explanations were not settled findings.
Design
Narrative review of neurophysiology and sensory-processing studies
Sample
Studies using EEG, MEG, fMRI, psychophysics, and behavioural measures; mostly small child samples, with no pooled total
Where
International literature available by 2011, organised by auditory, tactile, visual, multisensory, and attention findings
A 2021 systematic review found 29 studies of autistic camouflaging and two broad ways of measuring it: the difference between inner traits and visible behaviour, and a person’s own report of the effort they make. Those approaches are related, but they are not interchangeable—and that matters when research links masking with gender or mental health.
Design
Systematic review of 29 quantitative and mixed-method studies
Sample
29 studies; 2,254 adults and 1,077 children or adolescents after overlapping samples were counted once
Where
International literature searched through 13 May 2021
Bargiela S, Steward R, Mandy W. The experiences of late-diagnosed women with autism spectrum conditions: an investigation of the female autism phenotype. Journal of Autism and Developmental Disorders 2016;46(10):3281–3294. doi:10.1007/s10803-016-2872-8Open full text
Fourteen autistic women diagnosed in late adolescence or adulthood described being quiet at school, learning social behaviour deliberately, and having other difficulties recognised before autism. Their accounts helped shape the “female autism phenotype” idea. They cannot tell us how every autistic woman presents—or whether any one trait is uniquely female.
Design
Qualitative interview study using Framework Analysis
Sample
14 autistic women aged 22 to 30, all diagnosed at age 15 or later and without an intellectual disability
A 2021 narrative review found that researchers used “hyperfocus” for several different attentional states and often did not define it at all. The authors proposed four features to make future studies testable. That proposal is a useful starting point—not a validated checklist, an ADHD criterion, or proof that hyperfocus and flow are the same thing.
Design
Narrative review and proposed operational definition
Sample
Literature on hyperfocus, flow, and related attention states; no pooled participant sample
Where
Research across ADHD, autism, schizophrenia, cognitive psychology, and flow available by 2019
Young S, Adamo N, Ásgeirsdóttir BB, et al. Females with ADHD: an expert consensus statement taking a lifespan approach providing guidance for the identification and treatment of attention-deficit/hyperactivity disorder in girls and women. BMC Psychiatry 2020;20(1):404. doi:10.1186/s12888-020-02707-9Open full text
A multidisciplinary group used a selective evidence review and a one-day consensus meeting to explain why ADHD is missed in girls and women. Its practical message is useful: look beyond the disruptive-boy stereotype and examine impairment across a whole life. Its recommendations are expert guidance, not findings from a new dataset or a systematic review.
Design
Expert consensus statement informed by a selective literature review and structured meeting
Sample
Multidisciplinary consensus group including clinicians, educators, occupational specialists, service users, and charity workers; no participant dataset
Where
United Kingdom meeting with an international evidence base
Rommelse NNJ, Franke B, Geurts HM, Hartman CA, Buitelaar JK. Shared heritability of attention-deficit/hyperactivity disorder and autism spectrum disorder. European Child & Adolescent Psychiatry 2010;19:281–295. doi:10.1007/s00787-010-0092-xOpen full text
A 2010 review pulled together the first family and twin evidence that ADHD and autistic traits share some inherited influences. The signal was meaningful. The molecular evidence was not yet ready to name the genes or explain any one person.
Design
Narrative review of family
Sample
Multiple studies; key twin samples included 6,771 children and 674 young adults
Where
International literature reviewed by a Netherlands-based research team
Beheshti A, Chavanon ML, Christiansen H. Emotion dysregulation in adults with attention deficit hyperactivity disorder: a meta-analysis. BMC Psychiatry 2020;20:120. doi:10.1186/s12888-020-2442-7Open full text
A 2020 meta-analysis found a large difference in emotion dysregulation between adults with ADHD and adults without it. The result is persuasive that the connection is real. It is less precise about why the connection exists or how it differs from one person to another.
Design
Systematic review and random-effects meta-analysis of case-control studies
Sample
13 studies; 2,535 adults across ADHD and comparison groups
Rowney-Smith A, Sutton B, Quadt L, Eccles JA. The lived experience of rejection sensitivity in ADHD - A qualitative exploration. PLOS One 2026;21(1):e0314669. doi:10.1371/journal.pone.0314669Open full text
A 2026 focus-group study asked five university students with ADHD to describe rejection sensitivity in their own words. They talked about withdrawing before rejection could happen, masking how much it hurt, and feeling the response in their bodies. The study opens a useful line of inquiry. It is far too small to establish a universal ADHD pattern or a separate diagnosis.
Design
Qualitative thematic analysis of two online focus groups
Sample
5 undergraduate students over 18 with formal ADHD diagnoses
Raymaker DM, Teo AR, Steckler NA, Lentz B, Scharer M, Delos Santos A, Kapp SK, Hunter M, Joyce A, Nicolaidis C. “Having all of your internal resources exhausted beyond measure and being left with no clean-up crew”: Defining autistic burnout. Autism in Adulthood 2020;2(2):132–143. doi:10.1089/aut.2019.0079
Autistic adults had been describing burnout to each other for years before research caught up. In 2020, a team built partly of autistic researchers wrote the first definition from those accounts.
Design
Qualitative
Sample
19 interviews with autistic adults (10 women, 7 men, 4 another gender, aged 21 to 65) and 19 public online sources
Maciver D, Singh Roy A, Johnston L, Boilson M, Curnow E, Johnstone-Cooke V, Rutherford M. Waiting Times and Influencing Factors in Children and Adults Undergoing Assessment for Autism, ADHD, and Other Neurodevelopmental Differences. Autism Research 2025;18(4):788–801. doi:10.1002/aur.70011
A team funded by the Scottish Government pulled the case notes of 408 completed neurodevelopmental assessments and timed every stage. The median wait was 252 days for adults and 525 for children, and adults being assessed for ADHD waited longest.
Design
Retrospective review of clinical case notes
Sample
408 completed assessments (206 children and adolescents, 202 adults) from 30 diagnosing teams
Shaw P, Stringaris A, Nigg J, Leibenluft E. Emotion dysregulation in attention deficit hyperactivity disorder. American Journal of Psychiatry 2014;171(3):276–293. doi:10.1176/appi.ajp.2013.13070966
In 2014, four researchers pulled together everything the literature had on ADHD and emotion. Their answer to the question was: it’s common, it does real damage, and the field can’t yet say what the relationship is.
Design
Narrative review with three meta-analyses
Sample
Dozens of studies, mostly of children; adult data from clinic samples
Hull L, Petrides KV, Allison C, Smith P, Baron-Cohen S, Lai MC, Mandy W. “Putting on My Best Normal”: Social Camouflaging in Adults with Autism Spectrum Conditions. Journal of Autism and Developmental Disorders 2017;47(8):2519–2534. doi:10.1007/s10803-017-3166-5
In 2017, ninety-two autistic adults described, in their own words, why they hide their autistic traits, how they do it, and what it costs them. The paper gave the field its working model of camouflaging.
Design
Qualitative
Sample
92 autistic adults (55 women, 30 men, 7 another gender), aged 18 to 79
Kapp SK, Steward R, Crane L, Elliott D, Elphick C, Pellicano E, Russell G. “People should be allowed to do what they like”: Autistic adults’ views and experiences of stimming. Autism 2019;23(7):1782–1792. doi:10.1177/1362361319829628
Diagnostic manuals list “stereotyped or repetitive motor movements” as a core feature of autism. In 2019, a team that included autistic researchers asked 31 autistic adults what stimming is for. The answer was consistent: it regulates.
Design
Qualitative
Sample
31 autistic adults (20 men, 10 women, 1 non-binary), aged 21 to 56; 19 interviewed, 12 in focus groups
Au-Yeung SK, Freeth M, Thompson AR. “Am I gonna regret this?”: The experiences of diagnostic disclosure in autistic adults. Autism 2025;29(8):2181–2192. doi:10.1177/13623613251337504
Twelve adults diagnosed autistic in adulthood talked, at length, about telling other people. A 2025 study from Sheffield followed what happened next: why they told, how it landed, and what it changed.
Design
Qualitative
Sample
12 autistic adults diagnosed in adulthood (6 women, 4 men, 2 non-binary), aged 20 to over 60
