Pezawas et al102 studied longitudinally recurrent brief depression in an adolescent community sample. Recurrent brief depression was defined according to DSM-IV-TR research criteria. The frequency of all depressive disorders was 21%; the frequency of recurrent brief depression was 1% without history of major depressive disorder and 1% with history of major depressive disorder. Compared with major depressive disorder, recurrent brief depression did

not occur more in females than in males (a typical feature of nonbipolar depression), and frequency of comorbid axis Inhibitors,research,lifescience,medical I disorders was different. The frequency of suicide attempts, compared with major depressive disorder, was 8% vs 12%. Recurrent brief depression was not CHIR-99021 clinical trial associated Inhibitors,research,lifescience,medical with bipolar disorders. However, use of fully structured interviews by lay interviewers underreports bipolar II disorder.4, 24, 25

Angst and Hochstrasser100 found Inhibitors,research,lifescience,medical that recurrent brief depression (defined as in DSM-IV-TR) had a lifetime community prevalence of 10% to 16%, it could shift to major depressive disorder and vice versa, had a 35% diagnostic stability, usually lasted 1 to 3 days, had different axis I comorbidity compared with major depressive disorder (more anxiety disorders), high frequency of suicide attempts (14% Inhibitors,research,lifescience,medical vs 21% in major depressive disorder), and high treatment seeking. Angst et al also found that recurrent brief depression was similar to major depressive disorder

on most validators such as age at onset, family history, and impairment of functioning. Carta et al103 found a community lifetime prevalence of recurrent brief depression of 8%. A literature review by Merikangas et al104 on recurrent brief Inhibitors,research,lifescience,medical depression these found that validation criteria did not discriminate between recurrent brief depression and major depressive disorder, that it did not appear to be a milder subtype of depressive disorders, and that it was unrelated to the premenstrual syndrome. The current status of recurrent brief depression is unclear. Seasonal affective disorder According to DSM-IV-TR, seasonal affective disorder is not a distinct disorder, but a specifier of the major depressive episode of bipolar disorders and depressive disorders. It is unclear if it is more common in bipolar disorders, but it seems to be more common in bipolar II disorder than in bipolar I disorder.