Schizoaffective disorder

• What is schizoaffective disorder?
• Diagnosis
• How many people have schizoaffective disorder?
• Treatments

What is schizoaffective disorder?

People with schizoaffective disorder experience a combination of the symptoms of schizophrenia and bipolar disorder. During an episode of the illness, they can have mood or 'affective' symptoms – depression or mania – and the symptoms of psychosis – hallucinations, delusions and confused and disorganised thinking – at the same time, or within a few days of each other.

There is some debate about whether schizoaffective disorder is a form of schizophrenia, a form of bipolar disorder or a completely separate condition (the Diagnostic and Statistical Manual of Mental Disorders (DSM) and the World Health Organisation International Classification of Diseases (ICD), the classification systems used by psychiatrists, describe schizoaffective disorder as being distinct from bipolar and schizophrenia). One theory is that people who are given the diagnosis of schizoaffective disorder comprise two groups – one group with schizophrenia who also have symptoms of depression and mania; the other with bipolar who also have symptoms of schizophrenia. Another theory is that people with schizoaffective disorder have both schizophrenia and bipolar disorder.

Some research suggests a 'psychosis continuum': that the same genes and risk factors contribute to all mental illnesses that involve the symptoms of psychosis, but other genes and life experiences determine the type and severity of those symptoms. Some researchers think schizoaffective disorder sits somewhere between schizophrenia and bipolar on that continuum.

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Diagnosis

Because people with bipolar disorder may experience the symptoms of psychosis, and people with schizophrenia may experience depression, psychiatrists often find it difficult to make a definite diagnosis of schizoaffective disorder, and a diagnosis that is given may change (see Mental health diagnoses page). One research study showed that only 36 per cent of people diagnosed with schizoaffective disorder received the same diagnosis when they were re-assessed two years later. At that stage, 42 per cent were diagnosed with schizophrenia. Another study showed 37 out of 61 people who had been diagnosed with schizoaffective disorder were later diagnosed with bipolar disorder.

Some researchers think doctors may give a diagnosis of schizoaffective disorder when they are unsure whether someone has schizophrenia and also major depression, or if someone has bipolar disorder with the symptoms of psychosis.

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How many people have schizoaffective disorder?

Due to the difficulties in diagnosis, it is hard to know how many people have schizoaffective disorder, but researchers estimate that about one person in every 200 develops it. Generally, doctors and researchers think it is less common than schizophrenia or bipolar disorder.

More women than men are given the diagnosis, and, as with bipolar disorder and schizophrenia, the symptoms usually start in late adolescence or early adulthood.

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Treatments

There are no specific treatments solely for schizoaffective disorder. People who are given a diagnosis of schizoaffective disorder are usually prescribed antipsychotic drugs to treat the symptoms of schizophrenia and mood stabilisers (such as lithium or carbamezepine) used to treat the symptoms of bipolar disorder. Olanzapine is sometimes used as it now licensed for both the treatment of schizophrenia and bipolar disorder. The exact medication or combination of medications prescribed will depend on the symptoms someone is experiencing and may also include antidepressants.

There have been very few research studies testing what treatment works best for schizoaffective disorder. One research project published in 2010 reviewed 33 studies, the majority testing medication, but the researchers were unable to conclude whether one type of drug was better than another. The research team could find no trials testing talking therapies specifically for people with schizoaffective disorder. However, trials researching the effectiveness of talking treatments such as cognitive behaviour therapy and family therapy for schizophrenia will have included people with a diagnosis of schizoaffective disorder, so these therapies are likely to be helpful for them too, in combination with medication.