Feigning ADHD and stimulant misuse among Dutch university students

The role of executive functions in mediating the relationship between adult ADHD symptoms and hyperfocus in university students

BACKGROUND

Hyperfocus, a state of intense, narrow and prolonged attentional focus, has been associated with symptoms of attention-deficit/hyperactivity disorder (ADHD) in both clinical and non-clinical populations. Hyperfocus may be explained by difficulties in executive control, typically observed in ADHD.

AIMS

To investigate (1) whether ADHD and executive functions (EF) are associated with hyperfocus and (2) whether EF mediate the relationship between ADHD symptoms and hyperfocus.

METHODS AND PROCEDURES

A non-clinical sample of 380 university students (264 females) completed self-reports of ADHD, EF, hyperfocus and hyperfocus during rewarding activities.

OUTCOMES AND RESULTS

Increased difficulties in EF and severity of ADHD symptoms were significantly and positively correlated with a higher frequency of hyperfocus. Moreover, EF difficulties partially mediated the relationship between ADHD and hyperfocus (after controlling for sex and substance use), but not the relationship between ADHD and hyperfocus during rewarding activities.

CONCLUSIONS AND IMPLICATIONS

Difficulties in EF partially explained the higher frequency of hyperfocus, but not of hyperfocus during rewarding activities, among university students reporting more severe ADHD symptoms. Future research should investigate whether and how specific EF and other ADHD-related neurocognitive difficulties (e.g., reward sensitivity) contribute to various types of hyperfocus experiences in ADHD. WHAT THIS PAPER ADDS?: This paper is a first attempt to explain the relationship between adult ADHD symptoms and hyperfocus experiences. Our findings suggest that, although highly correlated, existing self-reports of hyperfocus measure different aspects of this experience: hyperfocus and reward-related hyperfocus. We replicate previous findings that indicated a greater frequency of both types of hyperfocus in ADHD. Additionally, we demonstrate a connection between EF difficulties and different aspects of hyperfocus. Finally, we extend previous findings by proposing that EF difficulties partially explain the relationship between ADHD and hyperfocus, but not the relationship between ADHD and reward-related hyperfocus. We hypothesize that other neurocognitive difficulties (e.g., reward sensitivity) may contribute to explain the relationship between ADHD and different aspects of hyperfocus.

Could psychostimulant drug use among university students be related to ADHD symptoms? A preliminary study

We aimed to explore if psychostimulant use among student could be linked to attention deficit-hyperactivity disorder (ADHD) symptoms using a self-administered questionnaire sent by email to French students in 2021. Participants were asked about their psychostimulant use and the presence of ADHD symptoms using the Wender Utah Rating Scale and the Adult Self-Report Scale. Among the 4431 respondents, the prevalence of psychostimulant use was concerning and significantly associated with ADHD symptoms. This association could be related to undiagnosed ADHD or to psychobehavioral impairments induced by psychostimulant use underlining the need of ADHD screening and targeted prevention measures.

Cognitive Underperformance in a Mixed Neuropsychiatric Sample at Diagnostic Evaluation of Adult ADHD

(1) Background: The clinical assessment of attention-deficit/hyperactivity disorder (ADHD) in adulthood is known to show non-trivial base rates of noncredible performance and requires thorough validity assessment. (2) Objectives: The present study estimated base rates of noncredible performance in clinical evaluations of adult ADHD on one or more of 17 embedded validity indicators (EVIs). This study further examines the effect of the order of test administration on EVI failure rates, the association between cognitive underperformance and symptom overreporting, and the prediction of cognitive underperformance by clinical information. (3) Methods: A mixed neuropsychiatric sample (N = 464, ADHD = 227) completed a comprehensive neuropsychological assessment battery on the Vienna Test System (VTS; CFADHD). Test performance allows the computation of 17 embedded performance validity indicators (PVTs) derived from eight different neuropsychological tests. Further, all participants completed several self- and other-report symptom rating scales assessing depressive symptoms and cognitive functioning. The Conners' Adult ADHD Rating Scale and the Beck Depression Inventory-II were administered to derive embedded symptom validity measures (SVTs). (4) Results and conclusion: Noncredible performance occurs in a sizeable proportion of about 10% up to 30% of individuals throughout the entire battery. Tests for attention and concentration appear to be the most adequate and sensitive for detecting underperformance. Cognitive underperformance represents a coherent construct and seems dissociable from symptom overreporting. These results emphasize the importance of performing multiple PVTs, at different time points, and promote more accurate calculation of the positive and negative predictive values of a given validity measure for noncredible performance during clinical assessments. Future studies should further examine whether and how the present results stand in other clinical populations, by implementing rigorous reference standards of noncredible performance, characterizing those failing PVT assessments, and differentiating between underlying motivations.

Characteristics and outcomes of cases with methylphenidate abuse, dependence or withdrawal: an analysis of spontaneous reports in EudraVigilance

Methylphenidate (MPH) is a central nervous stimulant, which is mainly used in attention deficit hyperactivity disorder (ADHD) and narcolepsy. In recent years, rising MPH prescription volumes have drawn attention to possible misuse. We analyzed data on suspected MPH abuse, dependence or withdrawal reported to the EudraVigilance database (1996-2019), comparing case characteristics (e.g. age, indications and outcome). In 1531 cases from 35 countries (median: 29 years, 57.6% male), 42.3% had been diagnosed with ADHD and 8.0% with narcolepsy. Narcolepsy cases were older than ADHD cases (mean age: 47 vs. 22 years), and used co-medications more frequently (79.4 vs. 47.8%). Intravenous MPH administration was most common among individuals not diagnosed with ADHD or narcolepsy. A history of abuse, dependence or withdrawal of any substance was more often documented in fatal than in nonfatal cases (49.0 vs. 22.5%), whereas differences regarding the route of administration were less pronounced. Minors, who presumably received MPH for ADHD treatment, presented less frequently with serious outcomes than older cases or those without an approved indication. Prescribers should exercise caution in adult MPH users and should make a thorough co-medication assessment. Finally, more research on substance abuse in narcolepsy patients is required, which should include comorbidities and co-medication.

Feigning Adult ADHD on a Comprehensive Neuropsychological Test Battery: An Analogue Study

The evaluation of performance validity is an essential part of any neuropsychological evaluation. Validity indicators embedded in routine neuropsychological tests offer a time-efficient option for sampling performance validity throughout the assessment while reducing vulnerability to coaching. By administering a comprehensive neuropsychological test battery to 57 adults with ADHD, 60 neurotypical controls, and 151 instructed simulators, we examined each test's utility in detecting noncredible performance. Cut-off scores were derived for all available outcome variables. Although all ensured at least 90% specificity in the ADHD Group, sensitivity differed significantly between tests, ranging from 0% to 64.9%. Tests of selective attention, vigilance, and inhibition were most useful in detecting the instructed simulation of adult ADHD, whereas figural fluency and task switching lacked sensitivity. Five or more test variables demonstrating results in the second to fourth percentile were rare among cases of genuine adult ADHD but identified approximately 58% of instructed simulators.

Symptom and performance validity in samples of adults at clinical evaluation of ADHD: a replication study using machine learning algorithms

INTRODUCTION

Research has shown non-trivial base rates of noncredible symptom report and performance in the clinical evaluation of attention-deficit/hyperactivity disorder (ADHD) in adulthood. The goal of this study is to estimate and replicate base rates of symptom and performance validity test failure in the clinical evaluation of adult ADHD and derive prediction models based on routine clinical measures.

METHODS

This study reuses data of a previous publication of 196 adults seeking ADHD assessment and replicates the findings on an independent sample of 700 adults recruited in the same referral context. Measures of symptom and performance validity (one SVT, two PVTs) were applied to estimate base rates. Prediction models were developed using machine learning.

RESULTS

Both samples showed substantial rates of noncredible symptom report (one SVT failure: 35.7% - 36.6%), noncredible test performance (one PVT failure: 32.1% - 49.3%; two PVT failures: 18.9% - 27.3%), or both (each one SVT and PVT failure: 13.3% - 22.4%; one SVT and two PVT failures: 9.7% - 13.7%). Machine learning algorithms resulted in generally moderate to weak prediction models, with advantages of the reused sample compared to the independent replication sample. Associations between measures of symptom and performance validity were negligible to small.

CONCLUSIONS

This study highlights the necessity to include measures of symptom and performance validity in the clinical evaluation of adult ADHD. Further, this study demonstrates the difficulty to characterize the group failing symptom or performance validity assessment.

Prescription Stimulants in College and Medical Students: A Narrative Review of Misuse, Cognitive Impact, and Adverse Effects

Stimulants are effective in treating attention-deficit/hyperactivity disorder (ADHD). Psychiatrist Charles Bradley first made this discovery in 1937 when he found that children treated with amphetamines showed improvements in school performance and behavior. Between 1995 and 2008, stimulants to treat ADHD increased six-fold among American adults and adolescents at an annual rate of 6.5%. Stimulants without a prescription, known as nonmedical use or misuse, have also increased. The highest rates of nonmedical prescription drug misuse in the United States are seen most notably in young adults between 18 and 25 years, based on data from the Substance Abuse and Mental Health Services Administration in 2021. Aside from undergraduate students, nonmedical prescription stimulant use is prevalent among medical students worldwide. A recent literature review reported the utilization of stimulants without a prescription in 970 out of 11,029 medical students. The percentages of medical students across the country misusing stimulants varied from 5.2% to 47.4%. Academic enhancement, reported in 50% to 89% of college students with stimulant misuse, is the most common reason for nonmedical stimulant use. With the increasing use of stimulants among adolescents and adults, it is unclear what long-term outcomes will be since little data are available that describe differences in how side effects are experienced for prescribed and non-prescribed users. The present narrative review focuses on these adverse effects in this population and the reasonings behind misuse and nonmedical use.

Effort–Reward Imbalance at Work and Prescription Drug Misuse—Prospective Evidence from Germany

This study examines how work stress affects the misuse of prescription drugs to augment mental performance without medical necessity (i.e., cognitive enhancement). Based on the effort–reward imbalance model, it can be assumed that a misalignment of effort exerted and rewards received increases prescription drug misuse, especially if employees overcommit. To test these assumptions, we conducted a prospective study using a nationwide web-based sample of the working population in Germany (N = 11,197). Effort, reward, and overcommitment were measured at t₁ and the 12 month frequency of prescription drug misuse for enhancing cognitive performance was measured at a one-year follow-up (t₂). The results show that 2.6% of the respondents engaged in such drug misuse, of which 22.7% reported frequent misuse. While we found no overall association between misuse frequency and effort, reward, or their imbalance, overcommitment was significantly associated with a higher misuse frequency. Moreover, at low levels of overcommitment, more effort and an effort–reward imbalance discouraged future prescription drug misuse, while higher overcommitment, more effort, and an imbalance increased it. These findings suggest that a stressful work environment is a risk factor for health-endangering behavior, and thereby underlines the importance of identifying groups at risk of misusing drugs.

Scores in Self-Report Questionnaires Assessing Adult ADHD Can Be Influenced by Negative Response Bias but Are Unrelated to Performance on Executive Function and Attention Tests

Self-report questionnaires are in widespread use in the assessment of adults with suspected attention-deficit and hyperactivity disorder (ADHD). Notwithstanding the high degree of validity, these questionnaires are considered to possess, their stand-alone use in assessment for adult ADHD may result in false-positive diagnoses due to the risk of negative response bias. Most of the self-report questionnaires in typical use are based on the diagnostic systems DSM-5 or ICD-10. From a neuropsychological point of view, however, testing of various executive function abilities and attentional performance is important in the assessment of adult ADHD. The present study (N = 211) found no evidence linking executive function (working memory and inhibitory processes) and attentional performance (processing speed) to the results of a self-report questionnaire, the ADHS-LE. The number of failures on the three symptom or performance validity tests (SVT/PVT) used provided the sole, and significant, explanation for the response behavior reported on the ADHS-LE. Of these three SVT/PVTs (the German version of the Structured Inventory of Malingered Symptomatology, SIMS, the reliable digit span, and the standard deviation of simple reaction time), only the SIMS was found to be a significant predictor variable. In the clinical context of this study, 32.6% of subjects produced at least one invalid SVT/PVT result. The use of a more conservative criterion—failure on at least two of the three SVT/PVTs deemed to be feigning ADHD—reduced the proportion of participants generating invalid values to 5%.

Joint Consideration of Validity Indicators Embedded in Conners’ Adult ADHD Rating Scales (CAARS)

A decade of research has both illustrated the need for accurate clinical assessment of adult ADHD and brought forward a series of validity indicators assisting this diagnostic process. Several of these indicators have been embedded into Conners’ Adult ADHD Rating Scales (CAARS). As their different theoretical underpinnings offer the opportunity of possible synergy effects, the present study sought to examine whether the item- or index-wise combination of multiple validity indicators benefits classification accuracy. A sample of controls (n = 856) and adults with ADHD (n = 72) answered the CAARS, including the ADHD Credibility Index (ACI) honestly, while a group of instructed simulators (n = 135) completed the instrument as though they had ADHD. First, original CAARS items, which are part of the CAARS Infrequency Index (CII), and items drawn from the ACI were combined into a new CII-ACI-Compound Index. Secondly, existing validity indicators, including suspect T-score elevations and the CII, were considered in combination. Both approaches were evaluated in terms of sensitivity and specificity. The combination of four CII and five ACI items into the CII-ACI-Compound Index yielded a sensitivity between 41 and 51% and an estimated specificity above 87%. Suspect T-score elevations on all three DSM scales emerged as another potentially useful validity indicator with a sensitivity of 45 to 46% and a specificity > 90%. Deeming examinees non-credible whenever two or more validity indicators showed suspect results ensured low false-positive rates (< 10%), but reduced sensitivity significantly. Classifying respondents as non-credible as soon as any given indicator fell into the suspect range resulted in frequent false positives (> 11% of misclassified adults with ADHD). Depending on whether high specificity or high sensitivity is prioritized, such combined considerations offer valuable additions to individual validity indicators. High sensitivity provided by “either/or” combinations could prove useful in screening settings, whereas high stakes settings could benefit from “and” combinations.

Suspected feigning of autism in adults: a clinician survey, indications and proposed guidelines

Purpose

This paper aims to provide a discussion and summary of a clinician survey exploring the experiences of suspected feigned autism.

Design/methodology/approach

This study is an online survey targeting a range of autism professionals, with varying levels of experience, working in different clinical settings.

Findings

Approximately half of the professionals who completed the survey reported experiencing situations of suspected feigning of adult autism across a range of clinical contexts and with various motivations. In terms of best indications of potential feigning, most clinicians reported “textbook” self-descriptions of problem behaviours with vague examples, as well as inconsistent presenting problems and mismatch with any known developmental history. Approximately half of clinicians expressed the view that autism was more difficult to feign than a psychiatric disorder and had experienced situations involving differences in professional opinion as to an individual autism diagnosis.

Research limitations/implications

The survey is limited by a potential sample bias and no information regarding the clinical characteristics of those suspected to have feigned autism. However, these initial findings offer further questions for future research to pursue.

Originality/value

As an initial examination of practicing clinicians’ experiences of suspected feigned autism, the survey highlights the complexities of an autism diagnosis and suggests feigning is a potential clinical scenario. Some guidance as to when to suspect possible feigned autism is also offered, as well as a provisional assessment protocol.

Feigning Symptoms to Obtain Prescription Stimulants: A Vignette-Based Study on Its Conditions

This vignette-based study examined the willingness to feign symptoms to obtain a prescription following an analysis on who might use prescription stimulants to enhance performance ( N = 3,468). It experimentally manipulated three factors: the social disapproval of prescription stimulant use for enhancement purposes, the physicians’ diagnostic efforts, and the medical condition (attention-deficit/hyperactivity disorder and narcolepsy); respondent characteristics of self-control, personal morality, and self-efficacy were also measured. Our results showed that social disapproval of prescription drug use, a personal morality that disapproves of drug use, high self-control, and high self-efficacy were negatively associated with the willingness to use. Willingness increased especially in situations of social approval when there was a stronger personal approval of drug use, or surprisingly when physicians’ diagnostic efforts were higher. The feigning willingness was lower in situations of social disapproval and when personal morality disapproved of feigning. Thus, personal and situational characteristics are relevant to understand both behaviors.

Examining the Clinical Utility of Selected Memory-Based Embedded Performance Validity Tests in Neuropsychological Assessment of Patients with Multiple Sclerosis

Within the neuropsychological assessment, clinicians are responsible for ensuring the validity of obtained cognitive data. As such, increased attention is being paid to performance validity in patients with multiple sclerosis (pwMS). Experts have proposed batteries of neuropsychological tests for use in this population, though none contain recommendations for standalone performance validity tests (PVTs). The California Verbal Learning Test, Second Edition (CVLT-II) and Brief Visuospatial Memory Test, Revised (BVMT-R)—both of which are included in the aforementioned recommended neuropsychological batteries—include previously validated embedded PVTs (which offer some advantages, including expedience and reduced costs), with no prior work exploring their utility in pwMS. The purpose of the present study was to determine the potential clinical utility of embedded PVTs to detect the signal of non-credibility as operationally defined by below criterion standalone PVT performance. One hundred thirty-three (133) patients (M age = 48.28; 76.7% women; 85.0% White) with MS were referred for neuropsychological assessment at a large, Midwestern academic medical center. Patients were placed into “credible” (n = 100) or “noncredible” (n = 33) groups based on a standalone PVT criterion. Classification statistics for four CVLT-II and BVMT-R PVTs of interest in isolation were poor (AUCs = 0.58–0.62). Several arithmetic and logistic regression-derived multivariate formulas were calculated, all of which similarly demonstrated poor discriminability (AUCs = 0.61–0.64). Although embedded PVTs may arguably maximize efficiency and minimize test burden in pwMS, common ones in the CVLT-II and BVMT-R may not be psychometrically appropriate, sufficiently sensitive, nor substitutable for standalone PVTs in this population. Clinical neuropsychologists who evaluate such patients are encouraged to include standalone PVTs in their assessment batteries to ensure that clinical care conclusions drawn from neuropsychological data are valid.

Unique considerations in the assessment of ADHD in college students

Evidence-based practice in psychology (EBPP) has long focused on treatment, but evidence-based psychological assessment (EBPA) is also crucial given the important role of accurate and reliable diagnostic practices in treatment planning. In terms of the diagnosis of attention-deficit/hyperactivity disorder (ADHD), EBPA practices are well-established for children, and more recently for adults, but for college students in particular there are special considerations that warrant attention. College students with symptoms of ADHD have some challenges that are unique, and thus the assessment and diagnosis of ADHD in these students is unique. The aim of this review is not to cover all EBPA strategies for diagnosing ADHD in emerging adult college students; rather, we will focus on the unique considerations at play in college ADHD assessment. These include (a) conceptual matters such as the appropriateness of the DSM-5 criteria for college students, the limitations of our understanding of ADHD this population because of a lack of diversity in research studies, and the issue of late-identified ADHD; and (b) practical matters, such as specific documentation needs, how to gather and interpret self- and other-report of symptoms, how to assess impairment, and alternate explanations for ADHD-like symptoms in college students.