What is mental illness? It refers collectively to all diagnosable mental disorders. Mental disorders are health conditions that are characterized by alterations in thinking, mood, or behavior associated with distress and/or impaired functioning. According to the DSM-IV, Alzheimer’s disease exemplifies a mental disorder largely marked by alterations in thinking (especially forgetting). Depression exemplifies a mental disorder largely marked by alterations in mood. The DSM-IV is a book that psychiatrists and psychologists use to diagnose a disorder. Unlike other diseases, there isn’t a nice little blood test that will tell what it is and what medications to use for a cure. Symptoms of shizophrenia usually begin in late adolescence or early adulthood. Many times there is a stressor, for instance going off to college or starting a new job, that brings about the onset of this illness. About 1 in 100 people are afflicted with this illness, but occurrence in adolescence (under the age of 18) is less common and onset under the age of 13 is extremely rare. The symptoms are hallucinations or voices, delusions which are firm beliefs that are out of touch with reality, and paranoia, a fear that people are watching, harassing, or plotting against the individual; disorganized speech which is often seen as the inability to maintain a conversation usually the result of staying on a topic; difficulty planning and completing activities in an organized fashion. Also, there can be a reduction in emotional expression, lack of motivation and energy or loss of enjoyment and interest in activities, including social interaction. Earlier onset is often associated with a poorer outcome. However, recent studies have shown that earlier treatment may reduce the decline in functioning and long-term impairments commonly associated with schizophrenia. Therefore, accurate and early intervention and diagnosis are critical. Nobody is certain what causes schizophrenia but they do know that the brains of people with schizophrenia are different from the brains of those who do not have the disorder. Research suggests that schizophrenia has something to do with problems with brain chemistry and brain structure. It is as much an organic brain disease as multiple sclerosis, Parkinson’s disease, or Alzheimer’s disease. Interestingly, it seems that schizophrenia-like many other medical illnesses such as cancer, heart disease, and diabetes-is caused by a combination of problems, some inherited and others occurring during a person’s development. For example, some scientists think that schizophrenia may be triggered by a viral infection affecting the brain very early in life or by mild brain damage from complications during birth.