Social determinants of GHQ score by postal survey

BACKGROUND: To develop interventions to reduce the morbidity associated with depression and anxiety, more information is needed about the social and demographic determinants of these disorders and the relative contributions of different potential predictors. METHODS: Using stratified sampling from the Family Health Services Authority (FHSA) register, postal surveys were sent to 61,000 adults across the North Western Regional Health Authority. Psychological morbidity was assessed using the 12-item General Health Questionnaire (GHQ). Nine potential predictors of morbidity were rated, including socio-demographic details and the presence of longstanding limiting physical illness and of a confidante. Logistic regression analyses were used to consider each of the nine potential predictors separately and in combination. RESULTS: A total of 38,014 questionnaires were returned (63 per cent). After adjustment for all other variables the strongest predictors of a high GHQ score were the absence of a confidante (odds ratio (OR) 3.64), longstanding limiting physical illness (OR 2.93), unemployment (OR 1.91), being a student (OR 1.78), being female (OR 1.64), single parenthood (OR 1.55) and living alone (OR 1.32). GHQ scores were highest in the 18-34 age range. Ethnicity exerted no significant effect after adjustment for other variables. CONCLUSION: In keeping with other research the data suggest that sociodemographic factors are strong predictors of depression and anxiety. The most vulnerable population groups are those with longstanding limiting physical illness and no-one to talk to. This should help in identifying high-risk individuals and informing preventive strategies.