Predictors of admission to a high-security hospital of people with intellectual disability with and without schizophrenia.
Admission to secure hospital facilities is a rare outcome for people with intellectual disability with or without concomitant psychosis. The present study compares people with mild intellectual disability with and without schizophrenia resident in the Scottish and Northern Irish State Hospital, Carstairs, to matched mild intellectual disability controls, also with and without schizophrenia, in the community. It is hoped that this study may identify socio-demographic, clinical or historical predictors which may lead to admission to secure hospital facilities for people with mild intellectual disability. One hundred and eight subjects were identified from two previous studies which concerned State Hospital patients and patients with intellectual disability with and without schizophrenia. Four experimental groups were derived: (1) 14 individuals with comorbid intellectual disability and schizophrenia who had been resident in the State Hospital; (2) 34 comorbid community control subjects; (3) 33 individuals with intellectual disability and no psychosis who had been resident in the State Hospital; and (4) 27 community control subjects with mild intellectual disability. The four groups were compared on a range of socio-demographic, historical and clinical variables obtained from case records and subject interviews. Relative to community controls, people with intellectual disability and no psychosis in the State Hospital are likely to be single, to have a later age of first psychiatric hospital admission, and to have a history of previous suicide attempts, alcohol abuse or drug misuse. Subjects with comorbid intellectual disability and schizophrenia in the State Hospital are more likely to be male, to have an early age of first psychiatric admission, and to have no family history of either schizophrenia or intellectual disability. Strategies aimed at addressing suicidal behaviour, alcohol and drug misuse amongst people with intellectual disability may facilitate a reduction in the number of admissions to high-security hospitals in the UK. In people with comorbid intellectual disability and schizophrenia, males with an early age of onset and no known family history are more likely to require care and treatment in a secure psychiatric setting. Such comorbid subjects may be suffering from a particular malignant form of schizophrenia, manifesting in childhood as cognitive impairment prior to the early onset of psychosis in teenage years.