Study Finds Depression, Insomnia Increased Concurrently in Older Patients

Annelies Brouwer, MD

A new investigation detailed the associations between depression and insomnia in older patients, stating that both conditions increased concurrently over time.

However, no additional risk was observed over repeated 3-year intervals regarding either condition.

Depression and insomnia are common conditions, with both affecting approximately 1 in every 10 individuals. Previous research indicated that insomnia symptoms precede depressive episodes, and that symptoms will persist after a depressive episode is resolved.

Investigators believed that these associations suggest that insomnia may give rise to depression. As such, timely treatment of insomnia would be further warranted.

In the present study, an investigative team led by Annelies Brouwer, MD, MSc, of the Amsterdam Public Health Research Institute, tested whether insomnia symptoms of older individuals were associated with later depressive symptoms.

Brouwer and colleagues performed analyses based on data from an ongoing prospective cohort study titled the Longitudinal Aging Study Amsterdam (LASA).

The cohort featured a nationally representative sample of older adults aged 55-85 years who lived in 3 geographically distinct areas.

Eligible participants had at least 1 measurement of either symptoms of insomnia or depression. As such, a sample-size of 3081 patients were included in the unadjusted analysis.

The team assessed symptoms of depression and insomnia every 3 years over a 20-year period.

Symptoms of depression were measured using the Center for Epidemiological Studies Depression Scale (CES-D), which featured 20 items. Meanwhile, symptoms of insomnia were measured using a 3-item self-report questionnaire, which included questions on trouble initiating sleep, nightly awakening, and early morning awakening.

Covariates such as age, gender, education, medication, alcohol use, reported pain, and chronic diseases were included. Pain was estimated via 5 items from the Nottingham Health Profile pain scale.

Though 3081 participants were included in the unadjusted analyses, a total of 1939 were featured in the adjusted analyses, with investigators noting that the sample size decreased mostly due to mortality.

The mean age of participants was 70.7 years in the first wave, with 51.6% of participants being women.

Additionally, the median symptoms of depression score were 6 and the median symptoms of insomnia score 6, and 14.7% of individuals experienced clinically relevant depressive symptoms (CES-D ≥ 16).

Investigators observed that the severity of symptoms of depression and insomnia and their within-individual average change over time were moderately correlated (correlation of intercepts: rho 0.41, 95% CI: 0.36 to 0.46) (P < 0.001) .

Symptoms of depression were not found to be associated with an additional risk of higher symptoms of insomnia 3 years later (p = 0.329). Likewise, symptoms of insomnia were not found to be associated with an additional risk of higher symptoms of depression 3 years later (P = 0.919) Similar results were found when analyses were corrected for covariates.

“Our findings support the recommendation that clinicians should be aware of the connection between depression and sleep problems, and that it might be beneficial to screen for and treat symptoms of depression when faced with symptoms of insomnia and vice versa,” the team wrote. “These findings also suggest that future research should test clinical interventions in which the evaluation and treatment for depression and insomnia are conjoined.”

The study, "Symptoms of depression and insomnia in older age: A within-individual analysis over 20 years," was published online in the Journal of the American Geriatrics Society.