ADHD and Memory – Arizona Forensic Services, LLC

Snap Shot

The question: How does attention-deficit/hyperactivity disorder affect what a witness, complainant, or accused person encodes, remembers, and reports, and how vulnerable is a person with ADHD to suggestive questioning?

What the research shows: Working-memory deficits are among the most consistent findings in ADHD, and adults with ADHD learn and retain less on average, largely because of weaker encoding. Laboratory studies report more intrusions and false recall in children and adults with ADHD, and studies of prisoners and young people link ADHD symptoms to compliance and to self-reported false confessions. The group differences are generally moderate rather than global, and people with and without ADHD overlap substantially.

What it does not show: Direct eyewitness research on people with ADHD is sparse, and the research on interrogation has more consistently linked ADHD symptoms to compliance than to greater yielding to leading questions. Group findings cannot show that a particular person’s account is inaccurate or that a particular confession is false, and a diagnosis alone does not establish how attentive or medicated a person was at the time of an event or an interview.

The law: Every person is presumed competent to testify (Fed. R. Evid. 601; Mil. R. Evid. 601; A.R.S. § 13-4061), so ADHD ordinarily goes to weight. Expert testimony is governed by Rule 702 and Houser, and in Arizona by Chapple, Nordstrom, and Lindsey, which keep the expert to general principles rather than opinions on a particular witness’s credibility.

Issues for each side: Prosecutors can show that gaps and lapses can occur with ADHD, while recognizing that the research cannot say whether any particular gap reflects ADHD, ordinary forgetting, or something else and that free recall may contain intrusions; defense counsel can examine how a client with ADHD was questioned and whether compliance shaped a statement, without claiming that ADHD makes memory globally unreliable.

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental condition defined by a persistent pattern of inattention, hyperactivity and impulsivity, or both, that begins in childhood and interferes with functioning (American Psychiatric Association, 2022). It is common in children and persists into adulthood in many people. International studies estimate that about a quarter of youth and adult offenders in custody, prison, and probation settings have ADHD, nearly all with co-occurring conditions (Young & Cocallis, 2021), and people with ADHD also appear in court as complainants and witnesses in a wide range of cases.

The statement that ADHD impairs memory is accurate in part and easy to overstate. The research points to a specific pattern: difficulty in the executive processes that hold information in mind, direct attention while an event unfolds, and monitor what is retrieved, with average deficits that are moderate in size and vary widely from one person to the next. That pattern bears on what a person with ADHD is likely to have encoded, how a free narrative may differ from answers to focused questions, and how the person may respond to pressure in an interview or interrogation.

This paper summarizes research on working memory, encoding, retrieval, false memory, suggestibility, and compliance in children and adults with ADHD, with notes on interviewing and medication, and the federal, military, and Arizona law that governs how these issues reach the factfinder.

Working Memory and Executive Control

Working memory is the limited system that holds and manipulates information over a few seconds while a person reasons, listens, or plans. Deficits in working memory are among the most consistent neurocognitive findings in ADHD. Meta-analyses have found reliable deficits in verbal and visuospatial working memory in children (Kasper et al., 2012; Martinussen et al., 2005) and in adults (Alderson et al., 2013). In one carefully designed study of children aged 8 to 13, the working-memory difference between children with and without ADHD was large in that sample (d = 1.24), well above the average effect of about half a standard deviation found across meta-analyses (Pievsky & McGrath, 2018, discussed below), and working memory accounted in part for the children’s organizational problems, partly through its link to inattentive behavior (Kofler et al., 2018). A review of 34 meta-analyses found that people with ADHD performed worse than comparison groups across nearly all neurocognitive domains studied, with an average effect of about half a standard deviation and working memory among the larger effects (Pievsky & McGrath, 2018).

A medium-sized group difference means that the groups overlap substantially, and many people with ADHD perform in the typical range on any given test. The same review found larger effects in meta-analyses funded by drug manufacturers (Pievsky & McGrath, 2018), a reminder that the size of a reported deficit depends on how it was studied.

Encoding, Learning, and Recognition

Information must be attended to before it can be remembered. When attention fluctuates, encoding tends to be uneven: details present while attention was engaged may be retained well, while details present during a lapse may not be stored at all. A meta-analysis of long-term memory in adults with ADHD found poorer performance on verbal, but not visual, memory tests, and found that the long-term memory deficit was closely tied to a deficit in initial learning; the authors concluded that the difficulty arises mainly at encoding rather than in retrieving information once it has been learned (Skodzik et al., 2017). For the factfinder, the practical point is that a witness with ADHD may have a genuine gap for part of an event, and that a gap of this kind can occur with ADHD; the research does not allow an expert to say whether any particular gap reflects ADHD, ordinary forgetting, or something else, and whether a witness is evasive or credible is for the factfinder.

Older accounts held that recognition memory is relatively spared in ADHD, and in one study of adults, learning and recognition on a word-list test were similar in the ADHD and comparison groups (Pollak et al., 2008). A 2025 meta-analysis of 28 studies of children and adolescents, however, found poorer visual object recognition in ADHD, with a moderate average effect (d of about 0.49) that varied with the type of task and was more variable among medicated participants (Lobato-Camacho & Faísca, 2025). The fair summary is that recognition is not immune but that, as with other measures, the average difference is moderate and the overlap between groups is large.

Retrieval Errors and False Memories

Several studies have found that people with ADHD make more retrieval errors. Adults with ADHD in one study made more intrusions (reporting words that had not been presented) and more repetitions of words already reported, which the authors attributed to weaker executive control of retrieval (Pollak et al., 2008). A meta-analysis of 20 studies of verbal memory interference found that children and adults with ADHD showed somewhat more retroactive interference (new learning disrupting older material) and performed worse on tasks requiring control over what is remembered, while children with ADHD were, unexpectedly, less affected by proactive interference (Orban et al., 2022). The effects were small to moderate and varied with interference type and age.

False-memory studies using the Deese-Roediger-McDermott (DRM) procedure, in which people study lists of related words and may later report a related word that was never presented, point in the same direction. Adults with ADHD in one study recalled fewer studied words and produced more false memories than comparison participants, and were more confident in some false responses (Soliman & Elfar, 2017). In a study of 55 children, those with ADHD recalled fewer correct words and produced more false memories, and poorer inhibition was associated with more false recall; both groups, however, were more confident in their correct responses than in their false ones (Martin et al., 2026). These word-list tasks suggest a vulnerability to intrusions and source confusion in unsupported recall; they do not measure memory for a personally experienced event, and they do not show that a person with ADHD will add false details to an account of a real event.

Suggestibility, Compliance, and Questioning

Interrogative suggestibility refers to the tendency to accept leading questions and to change answers under negative feedback; compliance refers to going along with requests or pressure to avoid conflict or please an authority figure while privately disagreeing. In a study of 90 male prisoners, ADHD symptoms were associated with compliance but not with interrogative suggestibility, and prisoners with ADHD symptoms were more likely to report having made a false confession to police (Gudjonsson et al., 2008). In a study of 386 male prisoners in Scotland, a third reported having made a false confession at some point, most often to protect someone else; conduct disorder and ADHD were the strongest predictors, and the hyperactive-impulsive symptoms drove the ADHD association after conduct disorder was taken into account (Gudjonsson et al., 2021). In a national survey of more than 22,000 young people in Iceland, more severe ADHD was associated with a higher risk of both police interrogation and self-reported false confession, with the worst outcomes among young people with severe ADHD and conduct disorder (Gudjonsson et al., 2016).

These studies rely on unverified self-reports of past false confessions, some made for reasons other than interrogation pressure. They support treating ADHD, particularly with impulsivity and conduct problems, as a risk factor for an inaccurate statement; they do not show that ADHD causes false confessions or that any particular statement was false. Interrogation is addressed in the False Confessions resources.

Research on child witnesses with ADHD is limited. A review of individual differences in children’s suggestibility found that intellectual impairment and limited language were associated with greater suggestibility, while executive function was not consistently related to it and the role of mental health conditions was unsettled (Klemfuss & Olaguez, 2020). Children with ADHD are best interviewed with the open-ended methods described in Suggestibility of Children’s Memory; the research does not support treating them as categorically less credible.

Interviewing Witnesses and Suspects with ADHD

Interviews are likely to work best when they reduce demands on working memory and sustained attention: short, single-part questions, breaks, a quiet setting, and free narrative followed by open prompts tied to what the person has already said; multi-part questions, rapid questioning, and long sessions add load. Australian detectives surveyed about interviewing young people with ADHD reported that the condition made the cognitive interview harder to conduct and less efficient, and identified a need for specialized training (Cunial et al., 2020). That work describes perceptions, not tested effects on accuracy. For suspects, the compliance findings mean that a person with ADHD may agree with suggestions to end an uncomfortable encounter; recording the whole interview and avoiding premature disclosure of key evidence protect the value of both admissions and denials.

Medication and Clinical Status

Many people with ADHD take stimulant or other medication. In a meta-analysis of placebo-controlled trials in children and adolescents, methylphenidate improved performance on memory, reaction time, and response inhibition tasks, with effects ranging from small to moderate (Coghill et al., 2014). Medication status may differ between the event, the interview, and trial. The research does not permit an expert to say how a particular dose, or a missed dose, affected a particular memory, and questions about specific medications belong with a qualified prescriber or pharmacologist.

Limits of the Evidence

Most of the research uses neuropsychological tests and word lists rather than memory for experienced events, and very few studies have examined people with ADHD as eyewitnesses. Samples are often small, ADHD frequently co-occurs with other conditions, and studies differ in diagnosis and medication status. The interrogation studies are correlational and rely on self-reports. Group differences are typically moderate, and the distributions overlap; the research cannot establish whether a particular person with ADHD encoded a particular detail, misremembered it, or yielded to a particular question.

Questions to Ask About This Research

When the large working-memory deficit reported by Kofler et al. (2018) is cited, counsel should ask who was studied and whether the result applies to this person: the participants were children aged 8 to 13, the figure is a group average, and adults, adolescents, and medicated individuals may differ. When word-list findings such as Pollak et al. (2008), Soliman and Elfar (2017), or Martin et al. (2026) are used to suggest that an account contains false details, counsel should ask whether a laboratory list task supports conclusions about memory for a real event and whether anything in this account appeared only after questioning or discussion. When Gudjonsson et al. (2008, 2021) is offered to suggest that a confession is unreliable, counsel should ask what was counted (self-reported lifetime false confessions, often made to protect someone else) and whether an association with compliance shows anything about this statement, as opposed to the conditions under which it was taken. These questions are explained in “Reading Research Claims: A Guide for Attorneys” on this site.

ADHD, Memory, and the Law

Federal and Military Standards

Every person is competent to be a witness unless the rules provide otherwise (Fed. R. Evid. 601; Mil. R. Evid. 601), and a witness may testify only to matters within personal knowledge (Fed. R. Evid. 602; Mil. R. Evid. 602), so a witness’s ADHD ordinarily goes to the weight of the testimony, tested through cross-examination, rather than to its admissibility. Expert testimony about ADHD and memory is governed by Federal Rule of Evidence 702, as amended December 1, 2023, which requires the proponent to show that it is more likely than not that the testimony rests on sufficient facts or data and reflects a reliable application of reliable methods. Daubert v. Merrell Dow Pharmaceuticals, Inc. (1993) assigned the trial judge a gatekeeping role, and Kumho Tire Co. v. Carmichael (1999) extended that obligation to all expert testimony, including testimony based on technical or other specialized knowledge. In courts-martial, Military Rule of Evidence 702 tracks the federal rule; under Military Rule of Evidence 1102, the 2023 amendment became part of the military rule in 2025 (Joint Service Committee on Military Justice, 2025), and practitioners should confirm current text. Military judges also apply the six factors of United States v. Houser (1993), which address the expert’s qualifications, subject matter, basis, relevance, reliability, and probative value.

When the person with ADHD is a suspect, the compliance research bears on questions the law addresses directly. A waiver of Miranda v. Arizona (1966) rights must be voluntary and made with full awareness of the rights and the consequences of abandoning them (Moran v. Burbine, 1986). Because coercive police activity is a necessary predicate for finding a confession involuntary under the Due Process Clause (Colorado v. Connelly, 1986), ADHD alone does not make a statement involuntary, although it can bear on how the person responded to the circumstances of the interrogation and on the weight the factfinder gives the statement. In the military, a waiver after Article 31 and counsel warnings must be made freely, knowingly, and intelligently, and the accused must affirmatively acknowledge understanding the rights (Mil. R. Evid. 305(e)(1)).

Arizona

In an Arizona criminal trial every person is competent to be a witness (A.R.S. § 13-4061). Arizona Rule of Evidence 702 adopted the Daubert standard effective January 1, 2012, and was amended effective January 1, 2024, to conform to the 2023 federal amendment (Ariz. Sup. Ct. Order R-23-0004). State v. Salazar-Mercado (2014) permits general, educational expert testimony that satisfies Rules 702 and 403 even when the expert has not evaluated anyone in the case. State v. Chapple (1983), Arizona’s leading case on expert testimony about the reliability of eyewitness memory, held that excluding a qualified expert was an abuse of discretion on its facts, while leaving admission generally within the trial court’s discretion; State v. Nordstrom (2001) upheld limiting such an expert to general factors and barring an opinion on whether a particular witness was accurate. Experts may not opine on a particular witness’s credibility (State v. Lindsey, 1986, 149 Ariz. at 475). The court decides the voluntariness of a confession outside the jury’s presence, and if the statement is admitted the jury may hear evidence bearing on voluntariness and give the statement the weight it deserves (A.R.S. § 13-3988).

Special Issues in Legal Practice

The principles described above apply with equal force to every party in a legal proceeding. The science operates the same way regardless of who is asking the questions, and the research summarized here does not by itself favor either side. What differs between the parties is not the science but the vantage point — the particular places where these issues tend to surface, and the particular errors each party is best positioned to guard against. The two summaries below identify those recurring issues. They are offered for orientation, not as litigation strategy; in every case the controlling question is what the evidence in that case will, and will not, support, and the expert’s role is to inform the trier of fact rather than to advocate for either side.

Special Issues for Prosecutors

The research supports several propositions prosecutors can legitimately present. A complainant or witness with ADHD is competent to testify, and the condition does not make memory globally unreliable; the average differences are moderate, and the overlap with people without ADHD is substantial. Gaps for parts of an event, difficulty with sequence, and a less organized narrative can occur with uneven attention and encoding; the research does not show whether any particular gap or disorganized narrative reflects ADHD, ordinary forgetting, or something else, and the credibility of any witness remains for the factfinder. Prosecutors are well positioned to obtain accounts in conditions that support accuracy: early, recorded interviews with short, open questions, breaks, and little pressure.

The research also counsels caution. Laboratory studies find more intrusions and false recall in people with ADHD, so details that first appear after focused questioning or discussion warrant attention to their source. A statement from a suspect with ADHD, particularly a young suspect with impulsivity or conduct problems, should be evaluated in light of the compliance research and the conditions of the interrogation, and a recording of the full interview is the best protection for an admission the State intends to rely on. Testimony that recognition is entirely spared in ADHD goes beyond the research.

Special Issues for Defense

The research supports several propositions defense counsel can legitimately present. ADHD is associated with working-memory and encoding deficits and, in laboratory studies, with more intrusions and false recall, so the source of a detail that emerged only under focused or repeated questioning is a fair subject of inquiry. For a client with ADHD, the association between ADHD symptoms, compliance, and self-reported false confessions supports examining how the interrogation was conducted, how long it lasted, what information the interviewers disclosed, and whether the client simply agreed with suggestions.

The research also counsels caution about the limits that apply to the defense. Direct eyewitness research on people with ADHD is sparse, the interrogation research has more consistently linked ADHD symptoms to compliance than to yielding to leading questions, and the laboratory differences are moderate, with substantial overlap between people with and without ADHD. An expert cannot tell the factfinder that a particular witness’s memory is false or that a particular confession is untrue, and in Arizona and the military the expert’s testimony is limited to general principles. The same research applies to the client’s own account, which may contain gaps and intrusions of the kind the defense attributes to a complainant with ADHD.

This paper is for educational purposes only and is not legal advice. The author is a psychologist, not an attorney; summaries of law are general and must be verified against current authority or with a licensed attorney.

References

Alderson, R. M., Kasper, L. J., Hudec, K. L., & Patros, C. H. G. (2013). Attention-deficit/hyperactivity disorder (ADHD) and working memory in adults: A meta-analytic review. Neuropsychology, 27(3), 287–302. https://doi.org/10.1037/a0032371

American Psychiatric Association. (2022). Diagnostic and statistical manual of mental disorders (5th ed., text rev.). https://doi.org/10.1176/appi.books.9780890425787

Coghill, D. R., Seth, S., Pedroso, S., Usala, T., Currie, J., & Gagliano, A. (2014). Effects of methylphenidate on cognitive functions in children and adolescents with attention-deficit/hyperactivity disorder: Evidence from a systematic review and a meta-analysis. Biological Psychiatry, 76(8), 603–615. https://doi.org/10.1016/j.biopsych.2013.10.005

Cunial, K. J., Casey, L. M., Bell, C., & Kebbell, M. R. (2020). Investigative interviewing of youth with ADHD: Recommendations for detective training. Psychiatry, Psychology and Law, 27(5), 797–814. https://doi.org/10.1080/13218719.2020.1742241

Gudjonsson, G. H., Gonzalez, R. A., & Young, S. (2021). The risk of making false confessions: The role of developmental disorders, conduct disorder, psychiatric symptoms, and compliance. Journal of Attention Disorders, 25(5), 715–723. https://doi.org/10.1177/1087054719833169

Gudjonsson, G. H., Sigurdsson, J. F., Bragason, O. O., Newton, A. K., & Einarsson, E. (2008). Interrogative suggestibility, compliance and false confessions among prisoners and their relationship with attention deficit hyperactivity disorder (ADHD) symptoms. Psychological Medicine, 38(7), 1037–1044. https://doi.org/10.1017/S0033291708002882

Gudjonsson, G. H., Sigurdsson, J. F., Sigfusdottir, I. D., Asgeirsdottir, B. B., González, R. A., & Young, S. (2016). A national epidemiological study investigating risk factors for police interrogation and false confession among juveniles and young persons. Social Psychiatry and Psychiatric Epidemiology, 51(3), 359–367. https://doi.org/10.1007/s00127-015-1145-8

Joint Service Committee on Military Justice. (2025). Amendments to the Military Rules of Evidence since 1984 (G. E. Maggs, Ed.; 2025 ed.). https://jsc.defense.gov/Portals/99/MRE%20Amendments%202025.pdf

Kasper, L. J., Alderson, R. M., & Hudec, K. L. (2012). Moderators of working memory deficits in children with attention-deficit/hyperactivity disorder (ADHD): A meta-analytic review. Clinical Psychology Review, 32(7), 605–617. https://doi.org/10.1016/j.cpr.2012.07.001

Klemfuss, J. Z., & Olaguez, A. P. (2020). Individual differences in children’s suggestibility: An updated review. Journal of Child Sexual Abuse, 29(2), 158–182. https://doi.org/10.1080/10538712.2018.1508108

Kofler, M. J., Sarver, D. E., Harmon, S. L., Moltisanti, A., Aduen, P. A., Soto, E. F., & Ferretti, N. (2018). Working memory and organizational skills problems in ADHD. Journal of Child Psychology and Psychiatry, 59(1), 57–67. https://doi.org/10.1111/jcpp.12773

Lobato-Camacho, F. J., & Faísca, L. (2025). Object recognition memory deficits in ADHD: A meta-analysis. Neuropsychology Review, 35(3), 517–534. https://doi.org/10.1007/s11065-024-09645-3

Martin, P., Speranza, M., & Colombel, F. (2026). Susceptibility of ADHD children to memory error production on a DRM task. British Journal of Developmental Psychology, 44(3), 525–539. https://doi.org/10.1111/bjdp.70031

Martinussen, R., Hayden, J., Hogg-Johnson, S., & Tannock, R. (2005). A meta-analysis of working memory impairments in children with attention-deficit/hyperactivity disorder. Journal of the American Academy of Child & Adolescent Psychiatry, 44(4), 377–384. https://doi.org/10.1097/01.chi.0000153228.72591.73

Orban, S. A., Festini, S. B., Yuen, E. K., & Friedman, L. M. (2022). Verbal memory interference in attention-deficit hyperactivity disorder: A meta-analytic review. Journal of Attention Disorders, 26(12), 1549–1562. https://doi.org/10.1177/10870547221085515

Pievsky, M. A., & McGrath, R. E. (2018). The neurocognitive profile of attention-deficit/hyperactivity disorder: A review of meta-analyses. Archives of Clinical Neuropsychology, 33(2), 143–157. https://doi.org/10.1093/arclin/acx055

Pollak, Y., Kahana-Vax, G., & Hoofien, D. (2008). Retrieval processes in adults with ADHD: A RAVLT study. Developmental Neuropsychology, 33(1), 62–73. https://doi.org/10.1080/87565640701729789

Skodzik, T., Holling, H., & Pedersen, A. (2017). Long-term memory performance in adult ADHD: A meta-analysis. Journal of Attention Disorders, 21(4), 267–283. https://doi.org/10.1177/1087054713510561

Soliman, A. M., & Elfar, R. M. (2017). False memory in adults with ADHD: A comparison between subtypes and normal controls. Journal of Attention Disorders, 21(12), 986–996. https://doi.org/10.1177/1087054714556814

Young, S., & Cocallis, K. (2021). ADHD and offending. Journal of Neural Transmission, 128(7), 1009–1019. https://doi.org/10.1007/s00702-021-02308-0

Legal Authorities

Colorado v. Connelly, 479 U.S. 157 (1986).

Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993).

Kumho Tire Co. v. Carmichael, 526 U.S. 137 (1999).

Miranda v. Arizona, 384 U.S. 436 (1966).

Moran v. Burbine, 475 U.S. 412 (1986).

State v. Chapple, 135 Ariz. 281, 660 P.2d 1208 (1983).

State v. Lindsey, 149 Ariz. 472, 720 P.2d 73 (1986).

State v. Nordstrom, 200 Ariz. 229, 25 P.3d 717 (2001).

State v. Salazar-Mercado, 234 Ariz. 590, 325 P.3d 996 (2014).

United States v. Houser, 36 M.J. 392 (C.M.A. 1993).

10 U.S.C. § 831 (Article 31, Uniform Code of Military Justice).

Ariz. Rev. Stat. Ann. § 13-3988.

Ariz. Rev. Stat. Ann. § 13-4061.

Fed. R. Evid. 601, 602, 702.

Mil. R. Evid. 305, 601, 602, 702, 1102.

Ariz. R. Evid. 702.

Ariz. Sup. Ct. Order R-23-0004 (amending Ariz. R. Evid. 702, effective Jan. 1, 2024).

Related topics from Arizona Forensic Services: False Confessions · False Confessions: Suggestibility