Trends in Depressive Symptoms and the Factors Affecting Them in Older Adults: A Prospective Cohort Study

Objectives Depression is one of the leading causes of disability worldwide.Given the increasing growth of the aged population in the world, it is important to identify factors affecting the development of late-life depression.This study aims to determine the changes in depression rate over a five-year period in older adults from Amirkola City, Mazandaran, north of Iran, and to identify the effective factors.Methods & Materials This prospective study was conducted on 800 older adults (aged 60 and above) from phase 1 (2011) and phase 2 (2016) of the Amirkola health and ageing project (AHAP) cohort study.Depressive symptoms were assessed in two phases using the geriatric depression scale (GDS).Also, cognitive status was measured by the mini-mental state examination (MMSE), and physical activity by the physical activity scale for the elderly (PASE). ResultsThe prevalence of depression in the first phase of the cohort study was 39.2%, which decreased to 35.25% in the second phase (P=0.001).In the first phase, 25.5% of older adults had mild depression, 9.5% had moderate depression, and 4.2% had severe depression.In the second phase, these percentages changed to 23.7%, 7.2%, and 4.2%, respectively.The McNemar test results revealed that 20.4% of the older adults developed new depressive symptoms after five years, while 58.2% experienced persistent depression (P<0.001).Male gender and lower educational levels were found to be the risk factors of depression in older adults.Conclusion Over a five-year period, 20% of older adults in Amirkola developed depression and 58.2% experienced persistent symptoms.It is recommended that all physicians regularly screen for depression during medical visits with older adults and refer suspected cases to mental health specialists to prevent the onset or worsening of depressive symptoms over time.