Preliminary diagnostic performance of the MOXO continuous performance test in young adults undergoing ADHD assessment

Introduction Attention-deficit/hyperactivity disorder (ADHD) diagnosis in young adults is often challenging due to symptom overlap with affective disorders and the inherent subjectivity of clinical evaluations. While Continuous Performance Tests (CPTs) provide objective metrics, their preliminary diagnostic performance and concordance with clinical evaluations relative to self-report questionnaires require evaluation in clinical settings. This study explored the diagnostic performance of the MOXO-CPT and formally examined its incremental predictive value beyond commonly used self-report measures in young adults assessed for ADHD. Materials and methods A total of 118 young adults (aged 18–25 years) consecutively referred with attention-related complaints completed the MOXO-CPT and self-report scales (ASRS, WURS-25, STAI, RRS-SF). ADHD diagnoses were established via comprehensive semi-structured clinical interviews based on DSM-5 criteria by an experienced psychiatrist blinded to test and questionnaire scores. Multivariable logistic regression and Receiver Operating Characteristic (ROC) analyses evaluated independent predictors and discriminative performance relative to this clinical reference standard. Results ADHD was diagnosed in 58.5% (n=69) of the cohort, while the remaining 41.5% (n=49) comprised a clinical comparison group predominantly presenting with alternative psychiatric conditions (63.3%). Participants with ADHD showed poorer performance across all MOXO-CPT indices (attention, timing, impulsivity, and hyperactivity) compared to the non-ADHD clinical comparison group. In multivariable modeling, average or above-average performance on the attention and hyperactivity indices was independently associated with a lower likelihood of ADHD diagnosis. ROC analysis indicated that the MOXO-CPT attention index demonstrated favorable discriminative capacity relative to the clinical diagnosis (AUC = 0.87, sensitivity = 81.2%, specificity = 85.7%), whereas other indices showed acceptable-to-poor discriminative performance. Discussion In this help-seeking sample of young adults, the MOXO-CPT attention index demonstrated promising discriminative ability in differentiating ADHD from a non-ADHD clinical comparison group predominantly presenting with anxiety and depressive disorders. These preliminary findings suggest that distractor-embedded continuous performance testing may serve as a useful objective adjunct for distinguishing ADHD from common psychiatric mimics in outpatient settings, rather than a stand-alone tool or a general screening instrument for healthy populations.