A low or irritable mood and/or a loss of interest or pleasure in usual activities that lasts for weeks or months
Episodes of mood changes lasting for several years with periods of normal behavior in between)
- Bipolar disorder(manic depression)
Episodes of depression, usually severe, alternating with episodes of extreme elation.
- Seasonal affective disorder(SAD/winter blues)
It occurs when the number of daylight hours is lower.
The situation when depression and hallucinations or delusions co-occur.