Objective: To analyse how committed crimes and substance-related diagnoses are associated with the age on the first contact with the psychiatric hospital system and the age at diagnosing of schizophrenia among schizophrenics.
Method: In a register-based study including all Danes diagnosed with schizophrenia born after November 1, 1963, data on criminality, substance-related diagnoses and contacts with the psychiatric hospital system were analysed.
Results: Compared with the non-convicted schizophrenics the convicted were older on first contact with the psychiatric hospital system and older when the diagnosis of schizophrenia was first given. In contrast, having a substance-related diagnosis was associated with a younger age on first contact but did not influence the age at which the diagnosis of schizophrenia was given.
Conclusion: It is important that both psychiatrists and the judicial system are aware of possible psychotic symptoms in criminal and abusing individuals to enable earlier detection and treatment.