Psychologists have identified a number of ways in which a depressed mood undermine the ability to solve problems, learn and remember.
Some investigators have shown that college students in a hypnotically induced happy or sad mood have “statedependent” memory: Recall of a word list is much better if a student is in the same mood during recall as when the list was first learned (SN: 4/18/81, p.253). But the recall performance of mildly depressed college students does not appear to differ from that of their nondepressed classmates, say researchers at Temple University in Philadelphia.
Studies based on experimentally induced moods may apply to the memory processes of severely depressed people rather than to the everyday, mild mood drops of college students, report Lynn Hasher and co-workers in the March JOURNAL OF EXPERIMENTAL PSYCHOLOGY: GENERAL. The investigators completed three similar experiments using 578 subjects. Two standard self-report inventories were used to identify mildlys depressed and nondepressed students. All subjects read a short story containing happy, sad and neutral events in a protagonist’s life. After a short interval, and in some cases after two days, recall was tested. To see if moods could be intenselves as the person in the story. Under all conditions, mildly depressed and normal subjects remembered the same proportion of positive, negative and neutral items. The overall amount of material recalled did not differ either.
Midly depressed students did not selectively recall more negative items than nondepressed classmates. The study calls into question two major theories that link depressed mood to memory, say the researchers. The first proposes that negative thoughts about oneself and the world strongly influence what is stored in memory as well as which past experiences are recalled.
The second theory argues that one’s mood organizes incoming information and sets up bridges between related memories that are more easily crossed when the same mood is experienced. But neither negative thought patterns nor mildly depressed mood altered the recall performance of the students in the Temple study. Memory problems are well documented among severely depressed people, note the researchers, but “mild variations in mood seem not to have a profound impact on the recall performance of college students.”