Cyclothymic temperament and major depressive disorder: A study on Italian patients

Classical authors had hypothesized that affective temperaments represent the subclinical manifestations of mood disorders: in particular, cyclothymic and hyperthymic temperaments have been considered as a subthreshold variant of bipolar disorder. The aim of our study is to test the presence of affective temperaments in a group of Italian patients with major depressive disorder (MDD), and to test the association between cyclothymic temperament and well-established valid tors of bipolar disorder diagnosis such as age at onset and family history of bipolar disorder. METHODS: Patients with diagnosis of major depressive disorder (DSM-IV-TR) were included in the study. Affective temperaments have been evaluated through the Italian semistructured interview version of the Temperament Evaluation of Memphis, Pisa, Paris and San Diego (TEMPS-I). In order to improve the accuracy of family history and age at onset reports, close family members of the patients were also interviewed. RESULTS: 104 of patients included in the study have completed the temperament interview. 25.5% were diagnosed with a dominant affective temperament. Cyclothymic affective temperament was the most represented in the sample of MDD patients (12.3%); depressive, hyperthymic and irritable temperaments have been detected respectively in 7.5%, 2.8% and 2.8% of patients. Patients with CT showed a significantly lower age at onset of MDD than "pure" MDD patients (31.9 vs. 40.9 years; p=0.049) and higher rates of family history of bipolar disorder in first degree relatives (15.4% vs. 0%; p=0.001). LIMITATIONS: The major limitation of this study was the lack of a group of bipolar depressives, which would have been useful in order to confirm the similarities of age at onset and bipolar family history with cyclothymic MDD. CONCLUSIONS: Our data confirm previous reports in a sample of accurately screened patients with unipolar major depression: we found that patients with a cyclothymic temperament had an earlier age at onset and a higher family history for bipolar disorder than patients without any dominant affective temperament. Further research is needed to ascertain whether patients with "unipolar" cyclothymic MDD respond to mood stabilizers.