What is mental illness?
Mental illness is a term used for a group of disorders causing severe disturbances in thinking, feeling, and/or relating. The result is a substantially diminished capacity for coping with the ordinary demands of life.

Is there a difference between mental illness and mental retardation?
Yes. People with mental retardation have diminished intellectual capacities. People who have a mental illness have normal intellectual capacities unless they have a "dual diagnosis" of both mental illness and mental retardation. However, some people with mental illness may have difficulty performing at a level expected based on their intelligence and education due to their illness, their medication, or lack of a supportive environment.

What causes mental illness?
The causes of mental illness are still not fully understood. Research on brain chemistry suggests that the brain's neurotransmitters do not function properly due to a biochemical imbalance in the brain. This sort of imbalance is comparable to imbalances in other areas of the body that cause illnesses such as diabetes and cancer. And, just as with diabetes, many symptoms of mental illness can be controlled with medication.

Other factors may contribute. Heredity may be a factor in mental illness, as it is in diabetes and cancer. Stress may contribute to the onset of mental illness in vulnerable persons. "Recreational" drugs may also contribute to onset but are unlikely to be the primary cause. Research no longer supports theories that family interaction and early childhood training are causes of mental illness.

Mood Disorders
Under the umbrella term of "mood disorders" are the most common groupings of psychiatric disorders. The primary symptom is that of changed affect or mood. These mood disorders may be bipolar disorder (formerly known as manic depression), in which the person swings between extreme high and low moods, or depression in which the person has persistent low moods. The medical cause is attributed to chemical imbalances or structural defects that disrupt normal brain processing. The most common affective disorder is depression.

Bipolar Disorder
A Bipolar Disorder is more rare than depression. Persons diagnosed as having bipolar disorder usually have several of the following symptoms:

• boundless energy, enthusiasm, and need for activity
  
• decreased need for sleep
  
• grandiose ideas and poor judgement
  
• rapid, loud, disorganized speech
  
• short temper and argumentativeness
  
• impulsive and erratic behavior
  
• possible delusional thinking
  
• rapid switch to severe depression
  
• suicidal thoughts

Depression
Persons diagnosed as having depression usually have several of the following symptoms:

• difficulty in sleeping
  
• loss of interest in daily activities
  
• inability to concentrate
  
• psychotic symptoms (delusions, hallucinations)
  
• suicidal thoughts and actions
  
• feelings of worthlessness, guilt, hopelessness

Schizophrenia
People with schizophrenia do not have a "split personality," or an idiosyncratic way of thinking which is correctable through psychoanalysis. People experiencing an acute episode of schizophrenia have a sudden onset of severe psychotic symptoms. To be "psychotic" means to be out of touch with reality, or unable to separate real from unreal experience. People with this disease can experience periods of distorted sense of reality or ability to think and also hallucinations and delusions. People with schizophrenia sometimes exhibit an emotion that is inconsistent with his or her speech or thoughts. Or they may show "blunted" or "flat" affect, which refers to a severe inability to express any emotion.

While medications can usually control many of the symptoms of schizophrenia, none can cure it. People who have this illness benefit from a combination of medications and a variety of programs and therapies such as psycho-social programs that concentrate on developing social and job skill training, individual psychotherapy, group therapy, and self-help programs.

Persons diagnosed as having schizophrenia may exhibit the following symptoms:

• disconnected and confusing language
• believing his or her thoughts are controlled by others
• poor reasoning, memory, and judgment
• eating and sleeping disorders
• hallucinations, delusions
• deterioration of personal appearance and hygiene
• loss of motivation
• poor concentration
• withdrawal
• sense of body boundaries deteriorating