Symptoms
The symptoms of
schizophrenia include delusions, hallucinations, thought disorders, loss of boundaries between
self and nonself, blunted or inappropriate emotional expressions, socially inappropriate behavior, loss of social interests, and deterioration in areas of functioning such as social relations, work, and self-care. The symptoms fluctuate in occurrence and in severity.
Delusions are false beliefs, usually absurd and bizarre. Thus a patient may believe that he or she is an important historical personality, or is being persecuted by others, or has died, or that a machine controls his or her thoughts.
Hallucinations are false sensory experiences. Most
schizophrenic hallucinations are auditory, but some are visual or olfactory. The content is often grandiose, hypochondriacal, or religious. Many hallucinatory voices speak of matters related to the patient's emotional problems or delusional concerns; others transmit apparently irrelevant messages.
Schizophrenic thought disorder may include a general lowering of intellectual efficiency, a free-associative rambling from one topic to another, a loss of the distinction between figurative and literal usages of words, reduced ability to think abstractly, invention of new words (called neologisms), and idiosyncratic misuse of common words.
Possible Explanations
Competing theories have been proposed to explain the causes of
schizophrenia. Psychoanalysts, including Sigmund Freud and Karl Abraham, have suggested that its origin lies in a lack of maternal affection in the first few weeks of life, or in childhood interpersonal relationships. Research data have not supported these claims, and biological interpretations now dominate.
Schizophrenic episodes have been correlated with increased levels of dopamine, especially in the brain's left hemisphere, and with lowered glucose metabolism in the brain's frontal lobes and basal ganglia. Notably enlarged brain ventricles are found in some patients, especially among those who tend to chronicity. However, ventricular enlargement is absent in many schizophrenics and is found in many unrelated conditions. These group differences are not sufficiently differentiating to be used for diagnosis, and there is no laboratory test for schizophrenia. Some investigators suspect that a slow-acting virus is responsible, while others point to evidence of subtle brain damage, as from birth injuries, in many schizophrenic patients.
A genetic factor is clearly involved. The incidence of schizophrenia is about 12% in the offspring when one parent is schizophrenic, about 50% when both parents are schizophrenic, about 10% in the brothers or sisters of a schizophrenic, and about 50% in persons who have an identical twin who is schizophrenic. Adoption studies show that family concordance of the disorder is largely accounted for by genes rather than by environment. Nevertheless, genes cannot be the sole cause of the disorder, since the concordance rate for identical twins is not 100%. Most researchers hold that both a biological predisposition and environmental factors interact to determine who becomes schizophrenic.
Varieties
Schizophrenia is heterogeneous in symptoms. Traditional subtypes include paranoid schizophrenia, in which delusions are prominent (see paranoia); catatonic schizophrenia, characterized by silent immobility for weeks or months (usually followed by a frenzied agitation; see catatonia); and hebephrenic (disorganized) schizophrenia, characterized by intellectual disorganization, chaotic language, silliness, and absurd ideas that often concern deterioration of the patient's body. In practice, most patients have some symptoms consistent with each of these categories. Many researchers believe that schizophrenia consists of different disorders that have not yet been distinguished and that do not correspond to the traditional subtypes.
Treatment
For many years psychotherapy was regarded as the preferred mode of treatmof schizophrenia (even though most patients could not afford it), and it continues to be used by some practitioners. Electroconvulsive treatment, or shock therapy, was introduced in 1937 and became the prevalent mode of treatment until the 1950s; it is still used in some cases. Psychosurgery (lobotomy and lobectomy), however, which became common in the 1940s and 1950s, is now in disrepute. Since the late 1950s schizophrenia has been treated primarily with one or another of a wide variety of antipsychotic medications, most of which are thought to block the action of dopamine in the brain. They do not cure schizophrenia, but they reduce the severity of the symptoms. Up to 20% of patients using the drugs at high dosages for long periods, however, develop motoric disorders known as tardive dyskinesia (TD). The diazapine drug clozapine avoids TD but may severely lower the number of white blood cells, sometimes to a life-threatening degree. Family therapy, in which family members learn to interact with the patient in a nonjudgmental, accepting manner, has also been found very helpful.
The recent trend has been toward keeping schizophrenic patients out of hospitals, but the popularity of doing so may be based more on civil libertarian concerns than on evidence of benefit. Up to one-third of diagnosed schizophrenia sufferers substantially recover, especially patients who had a good social and sexual adjustment prior to illness. Significant numbers improve even after years of severe illness, but some residual signs of the disorder usually remain.