This study aimed to evaluate the effect of an integrated Cognitive Behavioral Therapy (CBT) and Social Skills Training (SST) intervention in reducing social isolation among patients with schizophrenia in Indonesia.

A quasi-experimental design with a single-group pretest–posttest approach was employed. Thirty patients diagnosed with schizophrenia and experiencing clinically significant social isolation were purposively selected. The intervention consisted of 4 CBT sessions focused on identifying and restructuring cognitive distortions, followed by 5 SST sessions aimed at enhancing communication and interpersonal skills. Outcomes were assessed using the signs and symptoms, along with patients’ ability to cope with social isolation. Paired t-tests and Cohen’s d effect sizes were used for data analysis.

Following the intervention, participants exhibited statistically significant improvements across all domains (p < 0.001). Cognitive symptoms decreased by 74% (d = 1.8), affective symptoms by 65% (d = 1.5), behavioral withdrawal by 72% (d = 1.7), and social engagement improved by 80% (d = 2.1).

The integrated CBT-SST intervention effectively reduced social isolation and improved social functioning in schizophrenia patients. These findings support the implementation of combined psychosocial interventions in clinical practice, particularly in low-resource mental health settings.