Substance Use Disorder in Adult-Attention Deficit Hyperactive Disorder Patients: Patterns of Use and Related Clinical Features

Background: While a large amount of medical literature has explored the association between Attention Deficit/Hyperactivity Disorder (ADHD) and Substance Use Disorders (SUDs), less attention has been dedicated to the typologies of SUD and their relationships with ADHD-specific symptomatology and general psychopathology in dual disorder patients. Methods: We selected 72 patients (aged 18-65) with a concomitant SUD out of 120 adults with ADHD (A-ADHD). Assessment instruments included the Diagnostic Interview for ADHD in adults (DIVA 2.0), Conner's Adult ADHD Rating Scales-Observer (CAARS-O:S): Short Version, the Structured Clinical Interview for Axis I and II Disorders (SCID-I), the Barratt Impulsiveness Scale (BIS-11), the Brief Psychiatric rating scale (BPRS), the Reactivity Intensity Polarity Stability Questionnaire (RIPoSt-40), the World Health Organization Disability Assessment Schedule (WHODAS 2.0) and the Morningness-Eveningness Questionnaire (MEQ). A factorial analysis was performed to group our patients by clusters in different typologies of substance use and correlations between SUDs, as made evident by their typological and diagnostic features; in addition, specific ADHD symptoms, severity of general psychopathology and patients' functionality were assessed. Results: Two patterns of substance use were identified: the first (type 1) characterized by stimulants/alcohol and the second (type 2) by the use of cannabinoids (THC). Type 1 users were significantly younger and had more legal problems. The two patterns were similar in terms of ADHD-specific symptomatology and its severity at treatment entry. No differences were found regarding the other scales assessed, except for lower scores at MEQ in type 1 users. Conclusions: At treatment entry, the presence of different comorbid SUD clusters do not affect ADHD-specific symptomatology or severity.