What are some common symptoms of mental illnesses?

Symptoms common to more than one type major mental illness include: Fatigue; changes in eating habits; changes in sleeping patterns; lack of interest in previously pleasurable activities; distancing yourself from others; inability to maintain peaceful relationships with loved ones; extreme mood swings; unusual anger; sadness; irritability; confusion or fright; memory problems; unwanted memories/flashbacks or persistent thoughts; unexplained pain or body aches; substance abuse; suicidal thoughts; hearing voices that are not there.