We have shown that

1. First episode depression develops in an interaction between polymorphisms in the genes encoding the serotonin transporter and stressful life events.
2. First episode depression develops in an interaction between polymorphisms in the genes encoding the brain derived neutrophic factor (BDNF) and stressful life events.
3. No main effects of either the genetic polymorphisms or stressful life events on the outcome of antidepressants treatment.
4. Within 5 years of first episode depression 80% obtain remission, 30% experience recurrence of depression and 8.6% convert to bipolar disorder.
5. Recurrence increase with severity and treatment resistance of the first depression, and conversion to bipolar disorder with treatment resistance, a family history of affective disorder and co-morbid alcohol or drug abuse.