Feature

The Challenge of Schizophrenia

Finding out in advance who is susceptible to schizophrenia will help in early intervention.

Dr Robert Miller

Mention the word "schizophrenia" and you evoke many reactions: facile jokes, suspicion of the concept, and fear. However, there is no doubt that schizophrenia represents a very serious medical problem, with devastating effects on people with the disorder and their families, as well as having considerable economic impact. Early intervention may offer a chance to significantly reduce the problems associated with the condition.

Nebulous Definition

The shadowy nature of what we call schizophrenia is not surprising in view of the history of the concept. Unlike many illnesses, schizophrenia was never defined in terms of a known cause. Originally it was defined by a rather imprecise union of a complex of symptoms of mental disorder. An important feature was the tendency towards progressive decline in mental function. This is not a helpful definition if one wants to treat the illness, and is not now used.

Instead, there now exist a number of elaborate conventions of the exact combinations of symptoms required for the diagnosis. This has the advantage that different psychiatrists using the same conventions usually reach the same diagnosis. Nevertheless, these conventions are not based on any sound body of theory providing logical relation of symptoms, laboratory findings and so on to an underlying cause.

At present, the illness defined by such conventions can be related to a wide variety of possible causative factors: genetic factors, head injury, birth complications, immigration and many others. The great diversity of these influences perhaps indicates that conventional definitions have so far failed to capture the essence of the underlying disease process.

The most dramatic manifestation of schizophrenia is psychosis -- periods of severe mental turmoil, including hallucinations and delusions. Other less severe psychological symptoms prevail between these episodes. Psychosis usually responds quite well to medications. With the latest medications, there are far fewer problems with side-effects than in the past.

These medications have well-known properties, "blocking" the actions of a messenger substance in the brain called dopamine. This suggests that the psychotic episodes at least can be regarded as a brain disorder. Quite a solid body of theory exists relating psychosis to underlying abnormal brain processes. At present it is more difficult to define, in terms of brain abnormalities the underlying disorder from which the psychotic episodes arise.

Early Detection Important

Much of the disablement caused by schizophrenia occurs in the first few years of illness, especially if treatment is delayed. This is mainly due to repeated bouts of untreated psychosis. Such damage can be reduced if the best possible drug and psychological treatment is made available as soon as the illness appears. Research, pioneered in Australia in recent years, aims to identify people at the earliest stage of the illness, and offer them the best possible treatment before the damage is done.

At present one cannot predict who will develop the illness until the symptoms appear. It would be useful to have markers of exactly which individuals would develop the illness. Given such knowledge, onset of the illness might be prevented such as with very small doses of medication, or other measures.

It is known that schizophrenia has a tendency to run in families, but this is not a strong tendency, and does not allow prediction of exactly who will become ill. A number of psychological, physiological and personality traits are also known which differentiate those at increased genetic risk, from others in the general population. Taken singly, these are also only weak predictors of who will develop the illness. However, by combining all these weak predictors together, it might be possible to derive a method of prediction, with such low levels of errors that it could be useful in practice.

Programmes for New Zealand

Early intervention programmes for schizophrenia are under active consideration in New Zealand at present. They will identify young people with psychological problems or behavioural disturbance. Some of these may be in the earliest stages of psychotic illnesses such as schizophrenia. To make the early intervention strategy more effective, research tests could be conducted on all the young people identified in the program, using all the psychological and physiological markers known as weak predictors.

When it becomes clear who actually develops a serious illness, this data could be re-examined to discover which markers (or combination of markers) give the most accurate prediction of who will become ill.

In future years, the combined set of predictors could then be used to decide whether disturbed young people are at special risk of developing schizophrenia. Such information could then guide treatment decisions even before a major illness has appeared.

Dr Robert Miller is in the University of Otago's School of Medicine.