A case manager will be assigned to each of the participants in the intervention group. All case managers are psychologists. After discharge from the emergency department, the participants receive six sessions of proactive psychosocial intervention by their case manager over four months. Duration of each session is approximately 30 minutes. The intervention consists of telephone or face-to-face contacts with the case manager at scheduled intervals or when clinically necessary. If a patient declines medication therapy from the psychiatrist, case manager will provide psychotherapy using the model of cognitive-behavioural approach and problem-solving therapy. Case managers will receive backup and supervision by psychiatrist investigators and monthly supervision of therapy. Case managers will regularly monitor suicide risk, clinical status and provide follow-up.