30 Schizophrenia
Classification
Two systems for the classification of schizophrenia are widely used: the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM IV; American Psychiatric Association, 1994) and the International Classification of Diseases, 10th edition (ICD 10; World Health Organization, 1992).
Symptoms and diagnosis
Acute psychotic illness
These symptoms are commonly called positive symptoms.
Factors affecting diagnosis and prognosis
Causes of schizophrenia
Although the cause of schizophrenia remains unknown, there are many theories and models.
Drug treatment
Rationale for use of drugs
It is now accepted that antipsychotic drugs can control or modify symptoms such as hallucinations and delusions that are evident in the acute episode of illness. Except for clozapine and the other atypicals, there is little evidence for antipsychotic drugs being of value in the treatment of the negative symptoms, although the matter remains controversial (Chakos et al., 2001). Antipsychotic drugs increase the length of time between breakdowns and shorten the length of the acute episode in most patients.
Drug selection and dose
Side effects
Concerns about the EPSEs and toxicity of typical antipsychotic drugs led to calls over the past 10 years for the ‘atypicals’ to be prescribed more widely. This approach was supported in national guidance which advocated that atypical antipsychotic drugs should be used for the treatment of a first illness. However, increasing concern about the side effects of the atypical antipsychotic drugs, which includes weight gain, diabetes and sexual dysfunction, has led many clinicians to question the benefits of the newer and more expensive atypical antipsychotics. In more recent guidance (National Institute for Health and Clinical Excellence, 2009), it has been advocated that: