Prevention of first-episode depression: progress and potential.

Preventive intervention for first-episode depression is an exciting, emerging field. Many questions remain, however. Should we target patients who have sub-syndromal symptom elevations (i.e. indicated intervention) or should we intervene in high-risk groups (i.e. selective intervention)? Furthermore, should primary outcomes be incident depressions or long-term decreases in morbidity or mortality?