Diagnosis

There is no definitive test for diagnosing schizophrenia. Diagnosis is made by considering a person’s:

• Family history
• Emotional history
• Current symptoms
• Presence of other mental illness (differential diagnosis)

As symptoms may go unrecognised or are not obvious until the illness has reached an advanced stage, the diagnosis of schizophrenia can be very difficult. It may take a long time, as doctors usually wait to see the pattern and recurrence of symptoms.

Differential diagnosis involves distinguishing the symptoms of schizophrenia from those of other mental illnesses such as bipolar disorder. Some brain disorders, such as encephalitis (inflammation of the brain) also produce schizophrenia-like symptoms and must be ruled out. Drug abuse may also cause some symptoms which are similar to those of schizophrenia, for example delusions, hallucinations and unusual behaviour.