Depression symptoms can vary from mild to severe. According to the APA can include:
- Feeling sad or having a depressed mood
- Loss of interest or pleasure in activities once enjoyed
- Changes in appetite — weight loss or gain unrelated to dieting
- Trouble sleeping or sleeping too much
- Loss of energy or increased fatigue
- Increase in purposeless physical activity (e.g., hand-wringing or pacing) or slowed movements and speech (actions observable by others)
- Feeling worthless or guilty
- Difficulty thinking, concentrating or making decisions
- Thoughts of death or suicide
- Symptoms must last at least two weeks for a diagnosis of depression.
Also, medical conditions such as thyroid problems, a brain tumor or vitamin deficiency, can mimic symptoms of depression, so it is important to rule out general medical causes.