LETTER TO THE EDITOR. Social Support Deficits and Cognitive Impairment

Your journal has recently published two interesting papers, by Smits et al. (1995) and Orrell and Bebbington (1999, on social participation and cognitive functioning and social factors and dementia, respectively. We have just finished a study looking at social support deficits among those with cognitive impairment and handicap and would like to report our findings and relate them to those of the above-mentioned papers. We hypothesized that the reported association between social factors and cognitive impairment is mediated through disability and handicap. Thus, handicap may be a confounder of the association. Our survey is a relatively large ( N = 654) community-based cross-sectional study of all the elderly population living in a defined urban area in North London: the Gospel Oak area. We studied the exposure of subjects to a list of six social support deficits (extracted from James and Davies, 1987), cognitive impairment was measured using the dementia scale of Short-CARE (DDS) and handicap was measured following the recently validated London Handicap Scale (Harwood et al., 1994). In a univariate analysis, we found that having two or more social support deficits was significantly associated with cognitive impairment with an odds ratio (OR) of 1.9 (95% confidence interval (95% CI): 1.3-2.9). However, after adjusting for handicap in a logistic regression analysis, the association was no longer apparent (OR = 0.8, 95% CI: 0.5-1.5). We also found that exposure to two or more social support deficits was associated with a higher risk of being handicapped (OR = 2.8, 95% CI: 1.8-4.2). This association remained robust after adjusting for sex, cognitive impairment and age. Thus, our findings suggest that the reported associations from previous studies, including Smits et al. (1995), between lack of adequate social participation and poor cognitive performance may be due to a failure to adjust for handicap. In addition, our findings fail to replicate the ‘lack of excess disability’ among demented reported by Orrell and Bebbington (1995), as in our study handicap and cognitive impairment were robustly associated. By definition, handicap is a consequence of disability and impairment (ICIDH; WHO, 1980). We postulate that Orrell and Bebbington’s findings may have arisen from selection bias as their dementia sample was selected from day and inpatient services and compared to a sample from a different population. Our findings come from a community-based study, which minimizes the likelihood of this selection bias. Disability and handicap can arise from physical, mental and cognitive impairments. Sadly, it seems that people with disability receive less social support, perhaps as a consequence of their impaired capacity for social participation. We suggest that both disability and handicap from any kind of impairment rather than disability and handicap specifically arising from cognitive impairment are associated with social support deficits. This model could, therefore, explain the reported association between social participation and cognitive impairment. However, the limitations of a cross-sectional study have to be taken into account here and future longitudinal studies are needed in order to explain direction of causality. JORCE A. CERVILLA MARTIN PRINCE Institute of Psychiatry, University of London