Schizophrenia

Definition:

A group of psychotic disorders characterized by disturbances in thought, perception, affect, behavior, and communication that last longer than 6 months.

Causes, incidence, and risk factors:

The cause of schizophrenia is unknown. There are various theories to explain the development of this disorder. Genetic factors may play a role, as close relatives of a person with schizophrenia are more likely to develop the disorder. Psychological and social factors, such as disturbed family and interpersonal relationships, may also play a role in development . There are 5 recognized types of schizophrenia: catatonic, paranoid, disorganized, undifferentiated, and residual. Features of schizophrenia include its onset before the age of 45; continuous presence of symptoms for 6 months or more; and deterioration in functioning involving care of self, work, or social relationships.

Psychotic symptoms are present during the active phase and may include 2 or more of the following:

• delusions - unfounded beliefs that are thought to be true even in the face of contradictory evidence
• hallucinations - a sensory perception without an external stimulus; may affect hearing, taste, vision, smell, or sense of touch
• incoherence (not understandable) - disordered, and without logical connection
• catatonic behavior - bizarre motor behavior marked by a decrease in reactivity to the environment, or hyperactivity that is unrelated to stimulus
• flat affect - an appearance or mood that shows no emotion

No single characteristic is present in all types of schizophrenia. The risk factors include a family history of schizophrenia. Schizophrenia is thought to affect about 1% of the population. Childhood-onset schizophrenia begins after 5 years of age. It can be difficulty to differentiate from autism. Childhood-onset schizophrenia occurs equally in boys and girls. Often, there is a strong family history of schizophrenia.