Combining cognitive behavioral therapy and group training for social skills and cognition to improve negative symptoms in patients with psychotic disorders: a randomized controlled pilot trial

Patients with psychotic disorders may exhibit negative symptoms and cognitive deficits in addition to delusions and hallucinations. The innovative MOSAIC psychotherapy combines individual cognitive behavioral therapy and group training for social skills and cognition over eight months to improve negative symptoms, social cognition and social functioning. Sixty patients with psychotic disorders participated in a randomized controlled pilot trial comparing MOSAIC with SUPPORT (supportive conversations and pleasant group activities with equal duration and frequency). Statistical analysis revealed no significant differences between MOSAIC and SUPPORT regarding improvement in negative symptoms (p = 0.72, Cohen's d = 0.1). However, pre-post comparisons showed reduction in negative symptoms with medium to large effect sizes within each group. Mean PANSS negative scores decreased by 4.7 ± 5.8 points for MOSAIC (p < 0.001, d = 0.82) and by 4.1 ± 7.7 points for SUPPORT (p = 0.01, d = 0.53). In addition, a significant dose-response relationship with therapy adherence was observed in both groups. The current clinical pilot study showed no superiority of the new therapeutic approach over supportive treatment. Nevertheless, the results add to the empirical evidence that psychotherapeutic treatments with a combination of individual and group sessions can contribute to improvement of negative symptoms.