A number of studies of a possible relationship between duration of untreated illness (DUI) and various psychiatric disorders shown the possible role of DUI as negative prognostic factor in schizophrenia and psychotic disorders. on the other hand few data evaluate the role of DUI in the clinical outcome of major depressive disorder.

Analyze the duration of untreated illness and evaluate long-term outcomes in major depressive disorder.

Sample of 73 subjects (53F and 20M) with major depressive disorder according to DSM-IV-TR. We collected demographic, clinical and outcome data: Age, sex, family history, age at onset of illness, age of first antidepressant treatment and dosage, possible comorbidity with other diagnoses and substance abuse, number of depressive episodes before and after treatment, number of hospitalizations and suicide attempts.

Results show that the DUI is longer in the male than in the female sample (p = 0.049) and long DUI is related to an onset disorder at a younger age (p = 0.040) and with a longer duration of illness (p = 0.006). It was also demonstrated that the number of depressive episodes prior to the first antidepressant treatment is higher in the sample of patients with a longer DUI (p = 0.006).

These results show that the duration of untreated illness is longer in the male sample; other results are consistent with previous studies and show a better outcome of depression in patients with a short duration of untreated illness.