Clinical features of chronic and episodic depressi?ons

Purpose: Dysthymic disorder (DD) is a mild, chronic depressive condition. Proposedly, dysthymia will be defined as chronic depressive disorder together with chronic major depression in the DSM-5. The present study aims to investigate socialdemographic and clinical properties of depressive disorders in order to test the validity of diagnostic categories of episodic and chronic depression as proposed for the DSM-5.Method: Participants were 140 patients (113 female, 27 male) with a mean age of 37.91 (range=18-65, sd=13.22) and under treatment for depressive symptoms at the psychiatry clinic of the Adnan Menderes University Research Hospital. Each participant was assessed clinically by means of semi-structured SCID-I interviews, Hamilton Depression Scale, and Eskin Suicidal Behaviour İnventory.Findings: Of all the participants, 70% were diagnosed with major depression, 46% with dysthymic disorder and 16% with chronic major depression. Sixty five percent of the patients with DD have comorbid MDD, and 43% of the patients with MD have comorbid DD. In line with the DSM-5 proposal, 39% of the patients with pure major depression were defined as episodic depression (ED) group, whereas 61% of the patients with either pure dysthymia, double depression or chronic major depression comprised the chronic depression (CD) group. Comparisons between the two groups suggested an association of chronic depression with older age, lower education, higher depression scores, and comorbid anxiety disorders. Conversely the two groups did not differ in terms of gender and suicidality. As to the symptomatology, patients in the CD group admitted to loss of appetite less frequently, and pessimism, hopelesness, helplessness, anxiety and somatic complaints more frequently. As compared with the patients suffering from major depression, dysthymic patients were less likely to present with psychomotor agitation/retardation, anhedonia, loss of interest, insomnia and suicidal ideation.Conclusion: Findings of the present study suggest that the majority of the patients presenting with depressive symptoms suffer from chronic depression which is characterized by acute or chronic major depression superceded on and/or followed by dysthymia. Our findings support not only differentiation of dysthymia from major depression as diagnostic categories, but also differentiation of chronic depression from episodic depression. These divergent findings might reflect the conflict between cross-sectional and longitudinal perspectives in clinical practice and research. Clinicians and researches with cross-sectional perspective are more likely to notice differences between dysthymia and major depression whereas those with longitudinal perspective are more likely to be interested with differences between episodic and chronic depression. Incorporating both of these perspectives in a complementary manner into our diagnostic systems and clinical practice will possibly enhance our knowledge on depressive disorders and improve our threatment results.