The five recognized domains of negative symptoms are: blunted affect – showing flat expressions or little emotion; alogia – a poverty of speech; anhedonia – an inability to feel pleasure; asociality – the lack of desire to form relationships, and avolition – a lack of motivation and apathy. Avolition and anhedonia are seen as motivational deficits resulting from impaired reward processing. Reward is the main driver of motivation and this is mostly mediated by dopamine. It has been suggested that negative symptoms are multidimensional and they have been categorised into two subdomains of apathy or lack of motivation, and diminished expression. Apathy includes avolition, anhedonia, and social withdrawal; diminished expression includes blunt affect, and alogia. Sometimes diminished expression is treated as both verbal and non-verbal.Apathy accounts for around 50 percent of the most often found negative symptoms and affects functional outcome and subsequent quality of life. Apathy is related to disrupted cognitive processing affecting memory and planning including goal-directed behaviour. The two subdomains have suggested a need for separate treatment approaches. A lack of distress – relating to a reduced experience of depression and anxiety is another noted negative symptom. A distinction is often made between those negative symptoms that are inherent to schizophrenia, termed primary; and those that result from positive symptoms, from the side effects of antipsychotics, substance use disorder, and social deprivation – termed secondary negative symptoms. Negative symptoms are less responsive to medication and the most difficult to treat.
Schizophrenia was diagnosed far more in the US than in Europe which used the ICD-9 criteria. The US model was criticised for failing to demarcate clearly those people with a mental illness. In 1980 DSM III was published and showed a shift in focus from the clinically based biopsychosocial model to a reason-based medical model. DSM IV brought an increased focus on an evidence-based medical model. Historical treatment
In the 1930s a number of shock procedures which induced seizures (convulsions) or comas were used to treat schizophrenia. Insulin shock involved injecting large doses of insulin to induce comas, which in turn produced hypoglycemia and convulsions. The use of electricity to induce seizures was in use as electroconvulsive therapy (ECT) by 1938.Psychosurgery, including the lobotomy and frontal lobotomy – carried out from the 1930s until the 1970s in the United States, and until the 1980s in France – are recognized as a human rights abuse. In the mid-1950s the first typical antipsychotic, chlorpromazine, was introduced, followed in the 1970s by the first atypical antipsychotic, clozapine. Political abuse
From the 1960s until 1989, psychiatrists in the USSR and Eastern Bloc diagnosed thousands of people with sluggish schizophrenia, without signs of psychosis, based on "the assumption that symptoms would later appear". Now discredited, the diagnosis provided a convenient way to confine political dissidents. Society and culture
In 2002, the term for schizophrenia in Japan was changed from seishin-bunretsu-byō (精神分裂病, lit. mind-split disease) to tōgō-shitchō-shō (統合失調症, lit. integration–dysregulation syndrome) to reduce stigma.