Effects of late-onset depression and recovery on autobiographical memory

Autobiographical memory of old people (71-90 years) suffering from a major depression for the first time was compared to groups of demented (Alzheimer type) and normal old people, using a method of free narratives. The chronological distribution of memories across the life span was similar in the groups (a peak in adolescence and young adulthood, a decrease in midlife, and increase in the most recent years), but the depressed participants had a clearly enhanced recency effect. Whereas the rates of positive, neutral, and negative memories were identical in the three groups concerning remote events, the emotional valence of recent memories in the depressed group differed from that of the normal and demented subjects. The depressed group recalled proportionally more negative memories dating from the last 5 years (encompassing the depressive period). The depressed participants were reinterviewed 6 months later, when the majority had recovered from depression. At that point, the accumulation of negative recent memories had disappeared and become neutral. The results are discussed in relation to state and trait models of depressive processing.