Drug abuse in schizophrenia: comparison of patients who began drug abuse before their first admission with those who began abusing drugs after their first admission.

The relationship between the onset of drug abuse and onset of illness (first hospitalisation) and its correlates were examined in 42 hospitalised schizophrenics identified as drug abusers. 60% of the patients began drug use before their first hospitalisation. No differences on sociodemographic or clinical parameters between patients who began drug use before their first hospitalisation and those who began after it were detected when drug abuse was treated as a unitary phenomenon. Use of specific drugs was associated with significant differences in age, age at first hospitalisation, premorbid functioning and type of schizophrenia between patients who began drug pre-morbidly and those who began to use drugs post-morbidly. The differences were not uniform for the different drugs used. The findings are discussed in relation to vulnerability and self medication models of comorbidity of drug abuse and schizophrenia.