Prolonged sadness; unexplained crying spells
Significant changes in appetite and sleep patterns
Unexplained aches and pains
Irritability, anger, agitation, anxiety
Pessimism, indifference, worry
Loss of energy, persistent exhaustion
Feelings of guilt, worthlessness and/or hopelessness; social withdrawal
Inability to concentrate, indecisiveness
Inability to take pleasure in former interests
Excessive consumption of alcohol or use of chemical substances
Recurring thoughts of death or suicide (This symptom alone indicates the person should see a doctor - regardless of any other symptoms.)

Increased physical and mental activity
Exaggerated optimism and self-confidence
Grandiose thoughts, inflated sense of self-importance; increased energy
Excessive irritability, aggressive behavior
Decreased need for sleep without feeling tired
Racing speech, racing thoughts
Reckless behavior such as spending sprees, impulsive decisions, erratic driving and sexual indiscretions; impulsiveness, poor judgment
In severe cases, delusions and hallucinations
Denial that anything is wrong