Mental Health Care

Schizophrenia appears to be related to a cluster of causes rather than to a single cause. The current thought is that schizophrenia is a biological disease linked to genetic factors and the imbalance of neurotransmitters (chemicals) in the brain. In some people, the illness could also be caused by abnormalities in the prenatal environment or some distinct structural abnormalities in the brain. The role of stressful life-events has also been a subject of intense study as it is suspected that they could also be playing a secondary part in the precipitation of schizophrenia in vulnerable people.

Genetic Factors

It is clear from the studies of twins, family, and adopted children that genes and schizophrenia are intertwined. The risk of the onset of schizophrenia strongly depends on one’s genetic inheritance. Studies of families with the illness have found that a child who has one parent with schizophrenia, has a 10-13 per cent risk of developing the illness, whereas a child whose mother and father both have schizophrenia is at a 46 per cent risk of being similarly affected. The risk does not mitigate even if such children are adopted and raised by healthy parents. In comparison, children in the general population are only at about one per cent risk. It is likely that not one or two, but many different genes interacting with each other and with environmental risk factors result in schizophrenia.

The Dopamine Factor

There is mounting evidence to suggest that schizophrenia could be a result of an imbalance of chemicals in the brain. These chemicals enable brain cells to communicate with each other and are called neurotransmitters. The main culprit seems to be dopamine. Its overactivity in certain parts of the brain is the likely root cause of schizophrenia. The support for this hypothesis comes from several quarters. First, the effectiveness of antipsychotic drugs, which help in schizophrenia, hinges on blocking receptors for dopamine in the brain. Second, dopamine also plays a role in the mechanisms that govern attention and filtering of stimuli, the breakdown of which can lead to the illness. Third, amphetamines, which increase dopamine activity, intensify psychotic symptoms in people with schizophrenia. Despite these findings, scientists are yet to find out what causes the increase, or increased sensitivity of brain cells to dopamine in the first place.

Structural Abnormalities in the Brain

With the help of newer brain imaging techniques, researchers have discovered specific structural abnormalities in people suffering from schizophrenia. They tend to have larger cerebrospinal fluid cavities in the brain, a smaller overall volume of brain tissue and an abnormally low activity in the frontal lobe of the brain, which governs abstract thought, planning, and judgment. These defects may partially explain the abnormal thoughts, perceptions, and behaviour that characterize schizophrenia. However, these changes are not universal and may also be a result rather than the cause of the illness.

Prenatal Environment

Evidence suggests that pregnant mothers, who have poor nutrition or who get exposed to the influenza virus, are more likely to give birth to a child vulnerable to schizophrenia.

Psychosocial Stress

There has been a search for stressors and possible schizophrenic personality traits that may affect the onset and the course of illness. These efforts have largely drawn a blank, except for finding that stressful life circumstances can trigger episodes of schizophrenia in a person biologically predisposed to the disease. Individuals who have effective skills for managing stress may be less susceptible to its negative effects.

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