The purpose of this study is to determine whether genetic information associated with individual depressive symptoms.

The primary hypothesis is that the variations of the candidate genes are associated with individual symptoms in patients with depression.

The Second hypothesis is that patients with the associated genetic variation suffer longer from the associated symptom than the patients without the associated genetic variation.

Inclusion Criteria:

• Eligible patients were enrolled in the clinical trials program of hte Samsung Medical Center Geropsychiatry and Affective Disorder Clinics(Seoul, Korea). They received a semistructured diagnostic interview, the Samsung Psychiatric Evaluation Schedule. The affective disorder section of the Samsung Psychiatric Evaluation Schedule uses the Korean version of the structured clinical interview for the diagnostic and statistical manual of mental disorders, Fourth edition.
• interview with one more patient's family member for objective diagnosis and final diagnosis decision by agreements of two more psychiatric physicians

Exclusion Criteria:

• received psychotropic medication within 2 weeks of the study or fluoxetine within 4 weeks
• potential study participants for pregnancy, significant medical conditions, abnormal laboratory baseline values, unstable psychiatric features(eg.suicidal), history of alcohol of drug dependence, seizures, head trauma with loss of consciousness, neurological illness, or concomitant Axis I psychiatric disorder.