Effects of Group Interpersonal and Social Rhythm Therapy on Mood Symptoms and Suicide‐Related Interpersonal Constructs in Patients With Bipolar Disorder: A Quasi‐Experimental Study

ABSTRACT Background This study examined the effects of Group Interpersonal and Social Rhythm Therapy (IPSRT) on suicide‐related interpersonal constructs (perceived burdensomeness and thwarted belongingness as proxy indicators of suicidal risk) and mood symptoms in patients with bipolar disorder. Methods In this quasi‐experimental study, 36 patients with bipolar I or II disorder were recruited from psychiatric centres in Isfahan, Iran, and randomly assigned to an experimental group ( n = 18) or a control group ( n = 18). The experimental group received 12 weekly group sessions of Group IPSRT in addition to standard pharmacotherapy, whereas the control group received pharmacotherapy alone. Suicidal ideation was assessed using the STS‐IPTS, and mood symptoms were measured using the Persian version of the Mood Disorder Questionnaire (MDQ). Assessments were conducted at pretest, post‐test and follow‐up. Data were analysed using repeated‐measures ANOVA and MANOVA. Results Significant time × group interaction effects were found for suicidal ideation, F (1.53, 51.90) = 43.09, p < 0.001, η 2 = 0.56, and for perceived burdensomeness, F (2, 68) = 39.75, p < 0.001, η 2 = 0.54. Participants receiving IPSRT showed a marked reduction in perceived burdensomeness and thwarted belongingness that was largely maintained at follow‐up. For mood symptoms, a significant time × group interaction was found, F (1.68, 57.05) = 12.93, p < 0.001, η 2 = 0.28, with the strongest improvements observed in goal‐directed behaviour. Conclusions Group IPSRT appears to be an effective adjunctive intervention for reducing suicidal ideation and improving selected mood symptoms in individuals with bipolar disorder.