Depression in relation to purpose in life among a very old population: A five-year follow-up study

To investigate the relationship between purpose in life and depression and, in a five-year follow-up investigate whether purpose in life, adjusted for different background characteristics, can prevent very old men and women from developing depression.

A cross-sectional study included 189 participants (120 women and 69 men) 85-103 years of age living in a county in northern Sweden. Those who had not been diagnosed as depressed at baseline were included in the five-year follow-up study (n = 78). Depression was assessed using the Geriatric Depression Scale-15, the Organic Brain Syndrome scale, the Montgomery-Asberg Depression Rating Scale, and Diagnostic and Statistical Manual of Mental Disorders-IV criteria. Purpose in life was assessed with the Purpose in Life (PIL) scale.

In the cross-sectional study, 40 participants out of 189 (21.2%) were depressed, and those with depression had significantly lower PIL scores (mean score 107 vs. 99, p = 0.014). In the follow-up study, 78 persons were available for the assessment of depression. Of those, 21 (26.9%) were diagnosed as depressed and their mean PIL score at baseline was 106 (SD = 17.4) versus 108 (SD = 16.0, p = 0.750) among those not depressed. Using multivariate logistic regression analysis controlling for possible confounders, we found no association between purpose in life and the risk of developing depression after five years (OR = 1.0, 95% CI 0.97-1.03).

The results show a significant inverse relationship between purpose in life and depression in the cross-sectional study; however, a high PIL score does not seem to serve very old people as a protection against the risk of developing depression.