Remembering happy times may offer protection for mental health
by Markham Heid
When the going gets tough, the tough get nostalgic. That’s the take-home lesson from a recent spate of research papers that suggests recalling happier times may be an effective bulwark against stress and depression.
For a 2017 study in the journal Nature Human Behaviour, people were observed by an expressionless white-coated scientist while attempting to keep a hand submerged in ice water — an ordeal that reliably (and understandably) produced stress. Immediately afterward, the people were instructed to recall either happy memories or “neutral” memories, all of which they’d come up with ahead of time in preparation for the study. While levels of the stress hormone cortisol rose steadily following the unsettling ice water experience among the people who recalled neutral memories, cortisol levels barely budged among those asked to recall happier times.
The research team repeated the experiment in a second group, only this time they conducted brain scans during the memory-recall portion of the experiment. They found that several areas of the brain’s prefrontal cortex — areas involved in emotion regulation and “cognitive control” — became more active when people recalled positive memories. Acute stress “lessens our ability to use cognitive emotion regulation” and often triggers periods of anxiety or depression, the authors of that study wrote. But thinking about happier times seems to interrupt this cascade of negative thoughts and feelings.
This study’s findings dovetail with newer research linking depression to a hampered ability to recall positive memories. A 2019 study from the University of Cambridge in England found that the ability to remember pleasant events in detail is associated with lower cortisol levels and fewer negative self-appraisals in young people at risk for depression due to early life stress. “We were interested in resilience, or why certain people do not develop depressive symptoms after stressful life events,” says Adrian Askelund, the first author of the study, who is now a doctoral student in clinical psychology at the University of Oslo in Norway. “We found that those who recalled more specific positive events from their past had better mental health even after major stressors.”
Askelund says a “specific” memory — as opposed to a general one — is a memory that can be fixed in time and place and that recalls an event that lasts less than a day. For example, recalling a fun meal out with friends is a specific memory. “Depressed individuals tend to recall categorical memories, which are general memories that are not fixed in time or place and lack defining characteristics,” he says.
Memories of happy experiences — especially ones that involve social interaction — seem to benefit people because they reshape how we see ourselves for the better.
Going back 30 years, researchers have recognized that people with depression are more likely to recall negative memories as opposed to positive ones. There’s also evidence that people with depression may remember unhappy times as even worse than they actually were. All of this lends support to a popular theory of depression — known as the “competitive memory theory” — which holds that every person has access to both positive and negative thoughts and “self-representations,” but that people with depression tend to gravitate toward the negative ones. Over time, the activation of these negative mental pathways strengthens them; meanwhile, positive mental pathways grow weaker as they lie dormant.
Based on this competitive memory theory, some researchers have explored whether positive memory training can help protect people who are at high risk for depression. A 2018 study from a group of U.K. researchers found that training people to recall happy memories led to a significant drop in depression scores. The people in the study first learned to identify their negative self-appraisals, such as thoughts of worthlessness. Next, they recalled specific occasions when they’d demonstrated worth, or when their behavior otherwise refuted their negative self-talk. Over time, reliving these positive memories seemed to reduce the brain’s tendency to fire up its negative thought pathways.
Askelund says people undergoing cognitive behavioral therapy (CBT) for depression are often taught techniques designed to counteract negative self-related thoughts. Recalling positive memories may be one such technique. “Recalling specific positive memories seems to be a skill that can be trained,” he says.
The idea that people can train the brain to think in ways that counteract stress and depression is supported by research on gratitude. Multiple studies have found that taking time each day or week to think about the things in life for which one is grateful can improve mental health outcomes and well-being. “Whether stemming from our own internal thoughts or the daily news headlines, we are exposed to a constant drip of negativity,” says Robert Emmons, a gratitude researcher and professor of psychology at the University of California, Davis. Recalling happy memories — and creating new ones through positive experiences — can fuel feelings of gratitude and turn off the spigot of negativity, he says.
His views are backed up by research on how people spend time and money. “We know from a large body of research that people derive more happiness from experiential purchases — travel, meals out, concerts — than they do from clothing or electronic goods or material possessions,” says Amit Kumar, an assistant professor of marketing and psychology at the University of Texas at Austin.
Kumar says memories of novel and happy experiences — especially ones that involve social interaction — seem to benefit people because they reshape how we see ourselves for the better. “Experiences live on in our memories and in the stories we tell ourselves and other people,” he explains. Recalling positive experiences also naturally kindles feelings of gratitude, he adds.
All this research suggests that a happy, mentally healthy brain is one that regularly recalls moments that inspire positivity and feelings of gratitude. Especially during times of stress or sadness, redirecting one’s thoughts to better times or memories of gratifying experiences may prove to be a powerful safeguard against anxiety and depression.