Background: Bipolar disorder (BD) is a highly recurrent psychiatric condition. While combined pharmacological and psychosocial treatments improve outcomes, not much is known about potential moderators that could affect these treatments. One potential moderator might be the quality of interpersonal relations in families, for example, familial attitudes and perceived criticism. Method: To explore this question we conducted a post-hoc analysis that used an existing data set from a previous study by our group that compared cognitive behavioral therapy (CBT) and supporting therapy (ST) in remitted BD. In the present study, we used Cox proportional hazard models. Results: We found that the relatives’ ratings of criticism predicted the likelihood of depressive recurrences, especially in the ST condition. The patients’ ratings of negative familial attitudes predicted the risk of recurrences in general, irrespective of the therapy condition. Conclusion: These results suggest that it might be important to assess perceived criticism and familial attitudes as potential moderators of treatment outcome in BD.