New research from the journal Cognitive Behaviour Therapy illustrates a mental bias that could be present for those with depression when recalling autobiographical memories. When compared to those with no mental health diagnoses, individuals with major depressive disorder (MDD) reported less happiness when thinking about positive memories, but more sadness when recalling negative memories. One of the more prominent theories of depression, Beck’s cognitive model of depression, suggests that people who experience this disorder show a bias toward the processing of negative emotions about themselves, as opposed to positive emotions. 

Study authors Dahyeon Kim and K. Lira Yoon set out to provide additional information given by a previous study, which suggested that those with higher levels of depressive symptoms had different emotional responses to personal memories than those who do not experience depression. For the latter, the intensity of their positive feelings when recalling happy memories was greater than the intensity of their negative feelings when thinking about upsetting memories. However, those with depression experienced the same level of intensity of their emotional responses when remembering personal memories, whether they were happy or sad.

In Kim and Yoon’s experiment, they conducted interviews with thirty people with MDD, and forty-six control patients. During the interviews, participants were asked to recall their happiest, saddest, and most anxious moments. Once they were done describing these memories, they answered two questions. For the positive memory, they rated how happy they were when the actual event happened. Then, they were asked to rate how happy they felt recounting it. For the sad memory they were asked how sad they were during the incident, and how they felt now discussing it. They then did the same for the anxious memory. 

It is important to note that the two groups did not experience a difference in the intensity of their emotions at the time of the event. This discovery helps us see that both groups were recalling events of comparable emotional severity. However, the group with MDD experienced less happiness when reflecting on happy memories, but more sadness when reflecting on sad memories. Even after controlling for how much time had elapsed since the event, the results still showed this to be true. 

Previous studies have shown that reminiscing on positive memories did not improve low moods for individuals with depression. Kim and Yoon say that their findings may offer insight into this effect. They elaborate that the goals of increasing the happiness experienced from reminiscing may be beneficial, and can allow professionals to apply their discoveries to treatment plans in the future.