Insomnia symptoms and subsequent psychotropic medication: a register-linked study with 5-year follow-up

This study examined the associations of insomnia symptoms with subsequent psychotropic medication, reflecting mental health.Postal baseline surveys among 40- to 60-year-old employees of the city of Helsinki, Finland, were collected in 2000-2002 (N = 6,227, response rate 67%, 78% women) and longitudinally linked with national register data on prescribed reimbursed medication. Insomnia symptoms at baseline comprised difficulties in initiating and maintaining sleep, and non-restorative sleep. All purchased psychotropic medication 5-7 years prior to and 5 years after baseline was included. Outcomes were any psychotropic medication; antidepressants; and anxiolytics, hypnotics, and sedatives. Covariates included socio-demographic and work-related factors, health behaviors, lifetime mental disorders, and prior psychotropic medication. Logistic regression analysis was used to calculate odds ratios (OR) and their 95% confidence intervals (CI).Insomnia symptoms were associated with higher frequency of subsequent psychotropic medication prescriptions. The associations were strongest for frequent insomnia symptoms (women OR 3.55, 95% CI 2.64-4.77; men OR 4.64, 95% CI 2.49-8.66, adjusted for age and prior medication), but also rare and occasional symptoms were associated with psychotropic medication. Further adjustments had negligible effects.Insomnia symptoms were associated with prescribed psychotropic medication during follow-up in a dose-response manner. Attention should be given to the prevention of insomnia symptoms to curb subsequent mental problems.