Some Common Mental Illnesses

Each illness has its own symptoms, but common signs of mental illness in adults and adolescents may include the following:

• Excessive worrying or anxiety
• Feeling excessively sad or depressed
• Confused thinking or problems concentrating and learning
• Extreme mood swings, including uncontrollable "highs" or feelings of euphoria
• Prolonged or strong feelings of irritability or anger
• Avoidance of friends and social activities
• Difficulty understanding or relating to other people
• Changes in sleep habits or fatigue and lack of energy
• Changes in eating habits such as increased hunger or loss of appetite
• Changes in sex drive
• Difficulty perceiving reality (delusions or hallucinations in which a person experiences and perceives things that do not exist in objective reality)
• Inability to perceive changes in one's feelings, behavior, or personality ("lack of insight" or anosognosia)
• Excessive use of substances such as alcohol or drugs
• Multiple physical complaints with no obvious cause (e.g., headaches, stomachaches, vague and persistent "aches and pains")
• Suicidal thoughts
• Inability to perform daily activities or deal with daily problems and stress
• Severe anxiety about gaining weight or worrying about appearance

Mental illness can also develop in young children. Since they are still learning to recognize and talk about thoughts and feelings, the most obvious symptoms are behavioral. Symptoms in children may include the following:

• Changes in academic performance
• Excessive worry or anxiety, such as fighting to avoid bed or school
• Hyperactive behavior
• Frequent nightmares
• Frequent disobedience or aggression
• Frequent outbursts of anger

Source: National Alliance on Mental Illness (NAMI)