ADHD and addictive behavior in crack-cocaine users.

Background: Crack consumption is a major public health issue in Martinique with a poor prognosis. A preliminary study has found a high prevalence of history of childhood ADHD (C-ADHD) in crack users.

Objective: To determine the prevalence of C-ADHD and adult ADHD (A-ADHD) in crack users and their potential associations with substance use behavior.

Methods: All consecutive patients consulting in the public academic hospital covering 376,000 inhabitants were included in the present study and received a comprehensive battery measuring addictive behavior, psychiatric and somatic comorbidities. C-ADHD groups and A-ADHD groups were defined with the Wender-Utah Rating Scale-25 and the Brown ADD Rating Scale, respectively. Impulsivity was evaluated with the Barratt Impulsiveness Scale (BIS-11).

Findings: In total, 111 participants were evaluated. Among them, 50 (45%) were classified in the C-ADHD group and 20 (18%) in the A-ADHD group. Compared to the patients without ADHD, those with ADHD were found to have higher impulsivity (C-ADHD: BIS total score 67.90 (10.1) vs. 63.28 (10.5), P=0.021, BIS attentional score 17.5 (3.6) vs. 15.3 (3.4), P=0.002, A-ADHD: BIS total score 75.1 (11.3) vs. 63.4 (9.2), P<0.001, BIS motor impulsivity 26.9 (5.3) vs. 22.6 (4.3), P<0.001, BIS attentional score 19.3 (3.3) vs. 15.6 (3.5), P<0.001, BIS planification 28.9 (5.7) vs. 25.10 (4.7), P=0.003). Fifty percent of A-ADHD patients were found with high impulsivity vs. 15% of patients without A-ADHD (P<0.001). However, ADHD was not associated with more severe addictive behavior or history of legal consequences.

Interpretation: ADHD prevalence is high in cocaine-crack users and associated with increased impulsivity. However, neither ADHD nor impulsivity explains addictive behaviors or legal consequences.