Empirically derived symptom profiles in adults with attention-Deficit/hyperactivity disorder: An unsupervised machine learning approach.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is associated with various cognitive, behavioral, and mood symptoms that complicate diagnosis and treatment. The heterogeneity of these symptoms may also vary depending on certain sociodemographic factors. It is therefore important to establish more homogenous symptom profiles in patients with ADHD and determine their association with the patient's sociodemographic makeup. The current study used unsupervised machine learning to identify symptom profiles across various cognitive, behavioral, and mood symptoms in adults with ADHD. It was then examined whether symptom profiles differed based on relevant sociodemographic factors. METHODS: Participants were 382 adult outpatients (62% female; 51% non-Hispanic White) referred for neuropsychological evaluation for ADHD. RESULTS: Employing Gaussian Mixture Modeling, we identified two distinct symptom profiles in adults with ADHD: "ADHD-Plus Symptom Profile" and "ADHD-Predominate Symptom Profile." These profiles were primarily differentiated by internalizing psychopathology (Cohen's d = 1.94-2.05), rather than by subjective behavioral and cognitive symptoms of ADHD or neurocognitive test performance. In a subset of 126 adults without ADHD who were referred for the same evaluation, the unsupervised machine learning algorithm only identified one symptom profile. Group comparison analyses indicated that female patients were most likely to present with an ADHD-Plus Symptom Profile (χ2 = 5.43, p < .001). CONCLUSION: The machine learning technique used in this study appears to be an effective way to elucidate symptom profiles emerging from comprehensive ADHD evaluations. These findings further underscore the importance of considering internalizing symptoms and patients' sex when contextualizing adult ADHD diagnosis and treatment.

The Impact of Adverse Childhood Experiences on Symptom and Performance Validity Tests Among a Multiracial Sample Presenting for ADHD Evaluation.

OBJECTIVE: Adverse childhood experiences (ACEs) are commonly reported in individuals presenting for attention-deficit hyperactivity disorder (ADHD) evaluation. Performance validity tests (PVTs) and symptom validity tests (SVTs) are essential to ADHD evaluations in young adults, but extant research suggests that those who report ACEs may be inaccurately classified as invalid on these measures. The current study aimed to assess the degree to which ACE exposure differentiated PVT and SVT performance and ADHD symptom reporting in a multi-racial sample of adults presenting for ADHD evaluation. METHOD: This study included 170 adults referred for outpatient neuropsychological ADHD evaluation who completed the ACE Checklist and a neurocognitive battery that included multiple PVTs and SVTs. Analysis of variance was used to examine differences in PVT and SVT performance among those with high (≥4) and low (≤3) reported ACEs. RESULTS: Main effects of the ACE group were observed, such that high ACE group reporting demonstrated higher scores on SVTs assessing ADHD symptom over-reporting and infrequent psychiatric and somatic symptoms on the Minnesota Multiphasic Personality Inventory-2-Restructured Form. Conversely, no significant differences emerged in total PVT failures across ACE groups. CONCLUSIONS: Those with high ACE exposure were more likely to have higher scores on SVTs assessing over-reporting and infrequent responses. In contrast, ACE exposure did not affect PVT performance. Thus, ACE exposure should be considered specifically when evaluating SVT performance in the context of ADHD evaluations, and more work is needed to understand factors that contribute to different patterns of symptom reporting as a function of ACE exposure.

Exploring Subfactors of Adult Cognitive Disengagement Syndrome and Impact on Neuropsychological Performance.

OBJECTIVE: This study investigated subfactors of cognitive disengagement syndrome (CDS; previously referred as sluggish cognitive tempo) among adults referred for neuropsychological evaluation of attentiondeficit/hyperactivity disorder (ADHD). METHOD: Retrospective analyses of data from 164 outpatient neuropsychological evaluations examined associations between CDS subfactors and self-reported psychological symptoms and cognitive performance. RESULTS: Factor analysis produced two distinct but positively correlated constructs: "Cognitive Complaints'' and "Lethargy." Both correlated positively with symptom reports (rs = 0.26-0.57). Cognitive Complaints correlated negatively with working memory, processing speed, and executive functioning performance (rs = -0.21 to -0.37), whereas Lethargy correlated negatively only with processing speed and executive functioning performance (rs = -0.26 to -0.42). Both predicted depression symptoms, but only Cognitive Complaints predicted inattention symptoms. Both subfactors demonstrated modest to nonsignificant associations with cognitive performance after accounting for estimated premorbid intelligence and inattention. CONCLUSION: Findings indicate a bidimensional conceptualization of CDS, with differential associations between its constituent subfactors, reported symptoms, and cognitive performance.

Social Determinants of Health: Associations Between Dichotomous Versus Dimensional Scores, Neuropsychological Test Performance, and Psychiatric Symptoms.

This study examined the utility of dichotomous versus dimensional scores across two measures of social determinants of health (SDOH) regarding their associations with cognitive performance and psychiatric symptoms in a mixed clinical sample of 215 adults referred for neuropsychological evaluation (Mage = 43.91, 53.5% male, 44.2% non-Hispanic White). Both dimensional and dichotomous health literacy scores accounted for substantial variance in all cognitive outcomes assessed, whereas dimensional and dichotomous adverse childhood experience scores were significantly associated with psychiatric symptoms. Tests of differences between correlated correlations indicated that correlations with cognitive and psychiatric outcomes were not significantly different across dimensional versus dichotomous scores, suggesting that these operationalizations of SDOH roughly equivalently characterize risk of poorer cognitive performance and increased psychiatric symptoms. Results highlight the necessity of measuring multiple SDOH, as different SDOH appear to be differentially associated with cognitive performance versus psychiatric symptoms. Furthermore, results suggest that clinicians can use cut-scores when characterizing patients' risk of poor cognitive or psychiatric outcomes based on SDOH.

The impact of visual memory impairment on Victoria Symptom Validity Test performance: A known-groups analysis.

OBJECTIVE: We assessed the effect of visual learning and recall impairment on Victoria Symptom Validity Test (VSVT) accuracy and response latency for Easy, Difficult, and Total Items. METHOD: A sample of 163 adult patients administered the VSVT and Brief Visuospatial Memory Test-Revised were classified as valid (114/163) or invalid (49/163) groups via independent criterion performance validity tests (PVTs). Classification accuracies for all VSVT indices were examined for the overall sample, and separately for subgroups based on visual memory functioning. RESULTS: In the overall sample, all indices produced acceptable classification accuracy (areas under the curve [AUCs] ≥ 0.79). When stratified by visual learning/recall impairment, accuracy indices yielded acceptable classification for both the unimpaired (AUCs ≥0.79) and impaired subsamples (AUCs ≥0.75). Latency indices had acceptable classification accuracy for the unimpaired subsample (AUCs ≥0.74), but accuracy and sensitivity dropped for the impaired sample (AUCs ≥0.67). CONCLUSIONS: VSVT accuracy and response latency yielded acceptable classification accuracies in the overall sample, and this effect was maintained in those with and without visual learning/recall impairment for the accuracy indices. Findings indicate that the VSVT is a psychometrically robust PVT with largely invariant cut-scores, even in the presence of bona fide visual learning/recall impairment.

Impaired or invalid? Limitations of assessing performance validity using the Boston Naming Test.

The Boston Naming Test (BNT) has been proposed as an embedded performance validity test (PVT), though replication is needed to provide further empirical support of its simultaneous use as a cognitive ability measure and embedded PVT. This cross-sectional study examined BNT performance in a mixed neuropsychiatric sample of 137 patients with/without cognitive impairment. Four independent criterion PVTs classified 109 (80%) as valid and 28 (20%) as invalid. BNT raw and demographically-corrected T-scores were significantly higher among the valid group with small effect sizes (ηp2 = 0.04-0.05). Raw/T-scores differentiated valid/invalid groups, but with low classification accuracy (areas under the curve [AUCs] = 0.68/0.63), and unacceptably weak sensitivities (i.e. 7%/18%). When separated by impairment status, raw score accuracy appreciably increased (AUC = 0.87; 61% sensitivity/89% specificity) among unimpaired patients, whereas T-score accuracy, while significant, remained low (AUC = 0.68; 21% sensitivity/89% specificity). Conversely, among impaired patients, neither the raw (AUC = 0.59) nor T-score (AUC = 0.60) accurately identified invalid performance. In sum, BNT scores were not able to differentiate valid from invalid performance when cognitive impairment was present, and therefore showed limited overall utility as embedded PVTs. These findings further caution against inferring performance validity from measures in which a single score is used to assess both cognitive ability and validity.

Concordance between the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) and Clinical Assessment of Attention Deficit-Adult (CAT-A) over-reporting validity scales for detecting invalid ADHD symptom reporting.

This study investigated the relationship between symptom validity scales on the Clinical Assessment of Attention Deficit-Adult (CAT-A) and the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) in the context of Attention-Deficit/Hyperactivity Disorder (ADHD) evaluation. The sample comprised 140 consecutive patients referred for a neuropsychological evaluation of ADHD and were administered the CAT-A and the MMPI-2-RF and a battery of performance-based neurocognitive tests. Results indicated CAT-A/MMPI-2-RF symptom validity concordance of 51% between measures, with 38% concordant valid and 13% concordant invalid responses. Among those with discordance symptom validity results, rates of valid CAT-A/invalid MMPI-2-RF responding (41%) were more common than invalid CAT-A/valid MMPI-2-RF responding (8%). Results also indicated higher levels of ADHD symptoms among invalid responding within the CAT-A, whereas the MMPI-2-RF Cognitive Complaints scale did not differ by CAT-A validity status. Finally, symptom validity scales on both the CAT-A and MMPI-2-RF were largely discordant from neuropsychological test validity status per performance validity tests. Findings highlight the need for symptom validity testing when assessing ADHD and indicate that validity indices on broad personality assessments may assess different constructs than embedded validity indices in ADHD-specific measures.

Mean response latency indices on the Victoria Symptom Validity Test do not contribute meaningful predictive value over accuracy scores for detecting invalid performance.

The utility of the Victoria Symptom Validity Test (VSVT) as a performance validity test (PVT) has been primarily established using response accuracy scores. However, the degree to which response latency may contribute to accurate classification of performance invalidity over and above accuracy scores remains understudied. Therefore, this study investigated whether combining VSVT accuracy and response latency scores would increase predictive utility beyond use of accuracy scores alone. Data from a mixed clinical sample of 163 patients, who were administered the VSVT as part of a larger neuropsychological battery, were analyzed. At least four independent criterion PVTs were used to establish validity groups (121 valid/42 invalid). Logistic regression models examining each difficulty level revealed that all VSVT measures were useful in classifying validity groups, both independently and when combined. Individual predictor classification accuracy ranged from 77.9 to 81.6%, indicating acceptable to excellent discriminability across the validity indices. The results of this study support the value of both accuracy and latency scores on the VSVT to identify performance invalidity, although the accuracy scores had superior classification statistics compared to response latency, and mean latency indices provided no unique benefit for classification accuracy beyond dimensional accuracy scores alone.