Effectiveness of Cognitive Behavioral Therapy as an Adjunct Treatment for Delusions in Patients with Schizophrenia: A Quasi-experimental Pilot Study

Abstract

Delusions in schizophrenia often persist for a long time and are linked with emotional distress. Cognitive behavioural therapy for psychosis (CBTp) is recommended as an adjunct intervention to reduce the severity and impact of delusional beliefs, but evidence from India is limited. To examine the effectiveness of CBTp as an adjunct to treatment-as-usual (TAU) in reducing delusion-related psychopathology among individuals with schizophrenia. A quasi-experimental pilot study with a control group design. Twenty patients diagnosed with schizophrenia were recruited through purposive sampling from a tertiary mental health center and allocated to two groups: CBTp + TAU ( n = 10) and TAU-only ( n = 10). Assessments included the Scale for the Assessment of Positive Symptoms and Psychotic Symptom Rating Scales-Delusion Subscale (PSYRATS-DRS). The intervention group received 8–12 sessions of CBTp. Data were analyzed using the Mann–Whitney U and Wilcoxon signed-rank tests. Effect sizes were calculated. The intervention group showed significant pre–post improvement. Compared to TAU, adjunct CBTp group showed significantly greater improvement in delusional domains like preoccupation ( P = 0.029, r = 0.49), conviction ( P = 0.016, r = 0.54), distress ( P = 0.005, r = 0.63), and Psychotic Symptom Rating Scales (PSYRATS) total score ( P = 0.015, r = 0.55) with large effect sizes across PSYRATS domains and in total score. Adjunct CBTp is effective in reducing delusional severity in a selected subgroup of patients with schizophrenia.