Objective: To discuss special behavioural problems shown by a patient with Asperger's disorder from adolescence onward.
Method: The case and treatment of a 21-year-old male patient is described.
Results: A 21-year-old male developed obstinate stealing behaviours when he was 17 years old. He was regarded as a schizophrenic at first, and was suspected of kleptomania later. Asperger's disorder was diagnosed after we reconsidered the relationship between the schizoid psychopathy in childhood and the stealing behaviours which occurred in adolescence.
Conclusion: A wide variety of bizarre behaviours and so-called borderline behaviours occur in late adolescence and adult life of patients with Asperger's disorder. But classic schizophrenia is very rare. Psychiatrists unacquainted with the clinical diagnosis/context may find it difficult to evaluate ‘concrete’, ‘childish’, or ‘bizarre’ symptoms in patients with Asperger's disorder, and thus are prone to misdiagnose them as having schizophrenia disorders or other similar disorders.