Association of Affective Temperaments With One-Year Depressive Outcomes in Middle-Aged and Older Patients With Mood Disorders Without Psychiatric Comorbidities.

AIM: The course of depressive symptoms in mood disorders may be influenced by multiple clinical factors, making predictors of subsequent symptoms difficult to identify. This study examined whether affective temperaments are associated with depressive symptoms at one-year follow-up in middle-aged and older patients with mood disorders without clinically relevant psychiatric comorbidities. METHODS: This one-year longitudinal observational study included 91 patients aged 40-75 years with major depressive disorder (MDD) or bipolar disorder (BD) who were admitted to Hokkaido University Hospital for a recent major depressive episode, completed baseline assessments at discharge, and were followed for 1 year after discharge. Patients with clinically relevant psychiatric comorbidities were excluded. Affective temperaments were assessed using the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire. Multiple linear regression analyses were performed to examine factors associated with the 17-item Hamilton Depression Rating Scale (HAM-D17) total score at one-year follow-up, and logistic regression analyses to examine factors associated with subthreshold or more severe depressive symptoms at one-year follow-up. Temperament-by-diagnosis interaction analyses were performed to examine whether these associations differed between MDD and BD. This study was approved by the ethics committee of Hokkaido University Hospital. RESULTS: Depressive and cyclothymic temperaments were significantly associated with a higher HAM-D17 total score at one-year follow-up after adjustment. Depressive temperament was also associated with non-remission. A significant cyclothymic temperament-by-diagnosis interaction was observed. CONCLUSION: Depressive and cyclothymic temperaments may be clinically relevant for understanding residual depressive symptoms at one-year follow-up in middle-aged and older patients with mood disorders without clinically relevant psychiatric comorbidities. The significant cyclothymic temperament-by-diagnosis interaction highlights the potential diagnosis-specific relevance of affective temperament. Larger prospective studies are required to confirm these findings.