Gender differences in psychiatric diagnoses in older people with intellectual disability: a register study

BACKGROUND: Gender differences regarding psychiatric ill-health are well known in the general population. However, not much research is done on people with intellectual disability, and especially not among older people with intellectual disability. METHODS: People with intellectual disability aged 55+ years in 2012 in Sweden were identified through a register containing information on those receiving support and service for this type of disability. The cohort comprised 3609 women and 4327 men with mean age 65 and 64 years, respectively. Information on psychiatric diagnoses was collected from the National Patient Register for the period 2002–2012. Potential gender differences were evaluated both for diagnostic categories (e.g. affective disorders) and single diagnoses (e.g. depressive episodes). RESULTS: The most common diagnoses among women were in the diagnostic category affective disorders, and among men in psychotic disorders. The majority of both women (72%) and men (71%) had diagnoses in only one diagnostic category. Women were more likely than men to have at least one diagnosis of dementia (odds ratio 1.40, 95% confidence interval 1.06–1.83) or affective disorders (1.33, 1.21–1.58) during the study period. They were, however, less likely to have at least one diagnosis of alcohol/substance use related disorder (0.59, 0.43–0.80). No gender differences were found for diagnoses of psychotic (1.04, 0.86–1.27) or anxiety disorders (1.15, 0.94–1.40). Regarding single diagnoses, women were more likely than men to have had at least one diagnosis of unspecified nonorganic psychosis (1.75, 1.23–2.50), depressive episode (1.47, 1.19–1.82), recurrent depressive disorder (1.53, 1.06–2.22), other anxiety disorder (1.34, 1.06–1.69), or dementia in Alzheimer disease (2.50, 1.40–4.49), but less likely to be diagnosed with psychiatric and behavioral disorders due to use of alcohol (0.41, 0.27–0.61). CONCLUSIONS: As in the general population, there seem to be gender differences with respect to several types of psychiatric diagnoses among older people with intellectual disability. More research is needed to establish if this is due to gender differences in the occurrence of disease, inclination to seek care, health care utilization patterns, or ability to correctly identify disorders.