a person must have experienced at least 5 of the 9 following symptoms:
- depressed mood,
- lack of interest inmost activities,
- weight loss or gain,
- difficulty getting to sleep or sleeping more than usual,
- agitation,
- decreased energy level,
- extreme guilt or thoughts of worthlessness,
- diminished concentration,
- and thoughts of suicide or suicide attempts (American Psychiatric Association [APA], 2000)