Not everyone who is depressed or manic experiences every symptom. Some people experience a few symptoms, some many. Severity of symptoms varies among individuals and also varies over time.

• Persistent sad, anxious, or empty mood
• Feelings of hopelessness or pessimism
• Feelings of guilt, worthlessness, or helplessness
• Loss of interest or pleasure in hobbies and activities that were once enjoyed, including sex
• Decreased energy, fatigue, being "slowed down"
• Difficulty concentrating, remembering, or making decisions
• Insomnia, early morning awakening or oversleeping
• Appetite and/or weight loss, or overeating and weight gain
• Thoughts of death or suicide, suicide attempts
• Restlessness, irritability
• Persistent physical symptoms that do not respond to treatment, such as headaches, digestive disorders and chronic pain