Sex differences in the efficacy of cognitive behavioral therapy for adults with attention-deficit/hyperactivity disorder

Background and objectives Cognitive Behavioral Therapy (CBT) is an effective adjunctive treatment for Attention-Deficit/Hyperactivity Disorder (ADHD). This study examined sex differences in the efficacy of a brief 6-session CBT program versus a traditional 12-session format, combined with stable pharmacotherapy, in adults with ADHD. Methods A total of 81 adults (58 % male; 41.27 ± 9.26 years) were randomly assigned to 6- or 12-session CBT. ADHD symptoms, psychopathology, and functioning were assessed at baseline, post-treatment, and 3- and 6-month follow-up. Mixed-effects models analyzed interactions between time, treatment group, and sex. Results At baseline, females exhibited greater symptom severity (p = 0.019), higher inattention (p < 0.001), and more pronounced impairments (p = 0.004). CBT led to significant clinical improvements regardless of sex. A significant time-by-sex interaction emerged for inattention (CAARS:O:L, p = 0.043), although it did not remain significant after adjusting for baseline severity. Regarding time × group × sex interactions, females in the 6-session group showed smaller reductions in clinical severity during follow-up (CGI-S, p = 0.047); however, this effect was no longer statistically significant after controlling for baseline ADHD severity. Findings should be interpreted with caution given the limited female sample at follow-up and the significant influence of initial symptom burden on long-term trajectories. Conclusions CBT improves ADHD symptoms and related impairments in adults, with comparable overall benefits across sexes. Treatment response follow-up differences were better explained by baseline severity and treatment intensity rather than sex-specific differences.