SchizophreniaSchizophrenia is a devastating psychiatric disorder affecting approximately 1% of the population worldwide during a lifetime. The onset of the illness occurs relatively early in life, usually in the late teens or early adulthood, and most patients have long-lasting adverse effects. Schizophrenia is a clinical syndrome diagnosed on the basis of symptom profiles, and is characterized by a constellation of symptoms of psychosis, such as abnormalities in the perception or expression of reality, as well as negative symptoms, such as affective flattening and avolition. Cognitive deficits are also usually present, and the symptoms must have persisted continuously for a least 6 months: however, schizophrenia cannot be diagnosed if symptoms of mood disorder are present or the symptoms are the direct result of a medical condition or substance abuse (Box 1) [201].The specific causes of schizophrenia are not known and combinations of several factors are likely to be involved. Genetic factors play a major role in the development of the disease [1], and environmental factors are also of importance. These latter factors include a history of obstetric complications, such as asphyxia [2] and prematurity [3]. Advanced paternal age is also considered to be a risk factor [4], and birth during the spring and late winter also increases the risk [5]. Prenatal viral infections [6], serious viral infections of the CNS during childhood [7], migrant status and urban rearing [8], and a lifetime history of cannabis use [9] are other well-known risk factors.Contrary to previous interpretations, the incidence and prevalence of schizophrenia show marked variation between sites. For example, migrants have an increased incidence and prevalence of schizophrenia, and exposures related to urbanicity, economic status and latitude are also associated with various frequency measures [10]. Men have a higher risk than women [11], and a recent review concluded that men have a 40% higher incidence of schizophrenia than women [12].
SuicideSuicide is defined as a self-inflicted death with evidence that the person intended to die (Box 2) [13]. Suicide is among the leading causes of premature death in the world and it is estimated that approximately 1 million people die by suicide every year [202]. Suicide rates vary according to region, gender, age, time and ethnic origin, and also according to death registration practices. The annual suicide rate in the world is 14.5 out of 10,0000 (in 2000), which is equal to one suicide every 40 s. Suicide is approximately three-to four-times more common in men than in women [202]. Suicide rates vary between different regions, and underestimation of suicide rates is common due to under-reporting, lack of epidemiological data and misclassification [14]. It has been estimated from psychological autopsies that more than 90% of those dying by suicide have a diagnosable psychiatric disorder at the time of death, and approximately 60% of the Schizophrenia is a disorder with an estimated suicide risk of 4-5%. Many f...