Recalling Positive Memories May Reduce Risk of Depression

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Recalling specific positive memories and happy life experiences during adolescence may help teens fortify their resilience and reduce the risk of depression later in life, according to a new study (Askelund et al., 2019) led by researchers from the University of Cambridge.

This paper, “Positive Memory Specificity Is Associated with Reduced Vulnerability to Depression,” was published online ahead of print on January 14th in the journal Nature Human Behaviour.

For this study, lead author Adrian Dahl Askelund and senior author, Anne-Laura van Harmelen, who are both affiliated with the Department of Psychiatry at the University of Cambridge, collaborated with their colleague Professor Ian Goodyer and co-author, Susanne Schweizer from the Institute of Cognitive Neuroscience at the University College London. Van Harmelen is also a Fellow at Lucy Cavendish College and Director of the Risk and Resilience Group.

Depression Is the Number One Cause of Disability Worldwide

Depression has become an international epidemic. A systematic analysis of 301 acute and chronic diseases and injuries in 188 countries (Barber et al., 2015) found that depression is currently the leading cause of disability worldwide. Finding practical and affordable ways to help young people around the globe fortify their resilience and reduce depression risk is critical to the well-being of future generations.

Depressive symptoms often emerge for the first time during adolescence. Early-life adversity such as parents’ divorce, the death or separation from a family member, illness, and other negative life experiences increases the risk of depression for young adults. Adverse childhood experiences (ACEs) can also make someone more prone to crippling anxiety and hyperactive stress responses across his or her lifespan.

"Mental health disorders that first occur in adolescence are more severe and more likely to recur in later life,” Anne-Laura van Harmelen said in a statement. “With child and adult mental health services underfunded and overstretched, it is critical that we identify new ways to build resilience, particularly in those adolescents who are most at risk for depression."

For this study, Askelund et al. analyzed data from 427 young people (average age 14) living near the University of Cambridge, who were all considered to be at risk of depression. The researchers' main objective was to examine the effect of recalling positive memories on two signs of vulnerability to depression: negative self-related thoughts and high morning levels of the stress hormone cortisol.

The authors describe their study design and findings, “We used path modeling to examine whether recalling specific positive memories predicts reduced vulnerability to depression (high morning cortisol and negative self-cognitions during low mood) in adolescents at risk due to early life stress (n= 427, age 14 years). We found that positive memory specificity was associated with lower morning cortisol and fewer negative self-cognitions during low mood over the course of one year.” (For more see, "Cortisol: Why the 'Stress Hormone' Is Public Enemy No. 1")

What Are Negative Self-Cognitions?

According to the authors, “Negative self-cognitions refer to the tendency to blame and be derogatory about oneself (e.g., “I am useless”). Negative self-cognitions can be reactivated during stress in individuals who are in remission from depression and have been shown to predict first incidence of depression. In individuals at risk for depression with a negative thinking style, negative life events may be particularly detrimental.”

At the start of this experiment on positive memory specificity and reduced vulnerability to depression, all of the study participants were given a “cued recall Autobiographical Memory Test.” This memory test involves asking study participants to recall a specific memory associated with a particular word. According to the researchers, previous studies have shown that when someone is experiencing depression, he or she is likely to have more general recollections and fewer specific memories.

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The researchers also took saliva samples to measure baseline morning cortisol levels as a biomarker for stress at the beginning of the study and again a year after the experiment began.

Askelund and colleagues conducted semi-structured interviews at the beginning and end of their study. During these interviews, participants self-reported their frequency of moderate to severe adverse life experiences over the past 12 months. Additionally, participants were asked to self-report any depressive symptoms or negative self-related thoughts they’d experienced in the previous two weeks. These interviews were then repeated 12 months later when morning cortisol levels were measured again.

“We found that positive memory specificity was associated with lower morning cortisol and fewer negative self-cognitions during low mood over the course of one year,” the authors' said. “These findings indicate that recalling specific positive life experiences may be a resilience factor that helps in lowering depressive vulnerability in adolescents with a history of early life stress.”

In a press release, lead author Adrian Dahl Askelund said, "Our work suggests that 'remembering the good times' may help build resilience to stress and reduce vulnerability to depression in young people. This is important as we already know that it is possible to train people to come up with specific positive memories. This could be a beneficial way of helping support those young people at risk of depression."

Immediately after reading the press release for this study, "Recalling Happy Memories During Adolescence Can Reduce Risk of Depression," on the EurekAlert! website, I was curious to learn more from Askelund and van Harmelen about their research.

In an email correspondence, I wrote, "Anne-Laura, in a statement you said, 'Our research aims to understand why some young people with a history of childhood adversity develop mental health disorders, whereas others do not.' Your paper cites an international consortium which recently proposed a resilience framework to combat stress-related disorders where resilience is defined as ‘The maintenance or quick recovery of mental health following an adverse life event or a period of adversity.' (Kalisch et al., 2017). Based on this resilience framework, can you share a handful of factors that seem to help adolescents who are most at risk for depression build resilience?" Anne-Laura van Harmenel responded:

"With regards to what factors help; we actually conducted a systematic review of the literature to find out what the factors are that help adolescents with a history of childhood adversity. We found that there is empirical support for 13 individual-level factors (e.g., high self-esteem, low rumination), six factors on a family-level (e.g., high family cohesion, high parental involvement), and one community-level resilience factors (i.e., high social support) that benefit mental health in young people exposed to childhood adversity. In other work, we showed that friendships build mental health resilience in adolescents with a history of adversity. We are now researching in the lab if there are biological (e.g. brain structure, brain function, immune based) factors that help build resilience in adolescents with adversity."

I also asked Adrian Dahl Askelund, "Can you give Psychology Today readers one or two practical examples of how someone could fortify his or her ability to recall specific positive events and happy memories on demand?" Askelund responded:

"One increasingly popular habit which could potentially help with increasing access to positive memories is journaling. Although this is something that needs to be studied further, it may be beneficial to write down both positive and negative events that have happened, reflecting on how they affected your thoughts and mood. Importantly, this may not be that simple for people who struggle with clinical levels of depression. In these cases, our findings may be best applied in the context of established treatments, to potentially improve their effects." (For more on journaling see, "Expressive Writing Liberates the Mind from Chronic Worrying" and "Narrative Expressive Journaling Could Help Your Vagus Nerve.")

In closing: because it's notoriously difficult for researchers to recruit and retain study participants for longitudinal clinical research on adverse childhood experiences—and in an attempt to destigmatize the open discussion of personal mental health issues—for the final section of this post, I'm going to share my own struggles with clinical depression since adolescence along with autobiographical examples of how recalling happy memories has helped reduce my vulnerability to depression over the past four decades.

"Rose Tints My World & Keeps Me Safe From My Trouble and Pain." —The Rocky Horror Picture Show Soundtrack

The original release poster of the 1975 cult film, "The Rocky Horror Picture Show."

Source: Wikipedia Commons/Fair Use

One of my happiest memories from early adolescence is getting dressed up in gender-bending costumes and going to see the Rocky Horror Picture Show at the Exeter Street Theater in Boston on Friday nights during my freshman year of high school. Memorizing every line from this movie and going to the theater with other 'Rocky Horror devotees' was a bonding and empowering experience for me and a tight-knit group of friends who were social outcasts at our small, preppy private day school in Brookline, Massachusetts. Although my friends and I were categorized as the "freaks and geeks" clique by our classmates, we didn't care. We built camaraderie and a strong sense of community with other members of Boston's counterculture, which fortified our individual and collective resilience.

Of all the amazing lyrics on The Rocky Horror Picture Show soundtrack, the line "rose tints my world and keeps me safe from my trouble and pain," helped me avoid negative thinking styles and learn to look on the bright side by remembering happy memories throughout my adolescence.

Anecdotally, I can corroborate that young people with a history of early life stress who are at risk of experiencing clinical depression can benefit from recalling positive memories during adolescence.

As a teenager in the early 1980s, I suffered a triple whammy of adverse childhood experiences that included (1) parents' vicious divorce; (2) my father quit his job and moved to Australia to avoid paying alimony or child support; and (3) realized I was gay at a time of intense homophobia and fear of the burgeoning AIDS pandemic that was first reported by the New York Times on July 3, 1981.

To add insult to injury, during this period of adolescence, I was socially isolated at a stodgy boarding school in Wallingford, Connecticut and had a dean who chastised me for being a “sissy.”

As a sixteen-year-old in 1982, I was overwhelmed by dysphoria and fell into a suicidal clinical depression. Luckily, in the summer of '83, the movie Flashdance inspired me to start running while blasting the soundtrack on my Walkman headphones. That summer, I realized it was possible to recall vivid positive memories of happier times from my past by making mixtapes with lots of upbeat Top 40 music from my youth along with life-affirming and 'openness to experience' disco anthems of the era (e.g., "I'm Coming Out," "We Are Family," "I Am What I Am.")

As a practical and readily available way to combat my depressive symptoms as an adolescent, I created specific playlists and mixtapes that conjured up a smorgasbord of positive memories, which helped me recall specific when-where-and-what happy memories from my childhood. I purposely made myself a guinea pig in my own mental health experiment. It became evident through trial-and-error that on days when I consciously recalled specific happy memories, I was less likely to experience debilitating depressive symptoms.

Because each audio cassette became a stimulus that was associated with feeling good on a pyscho-physiological level, there was also a Pavlovian response in my autonomic nervous system that probably lowered my cortisol levels. Within a few milliseconds of putting a specific mixtape in my Walkman and having a song like "Holiday" or "Flashdance...What a Feeling" fill my ears, a flood of happy memories would fill my mind and I could instantly feel any dark mood become brighter.

To this day, I create playlists on my smartphone that are specifically designed to trigger the recall of happy memories from the "good old days." These songs never fail to make me feel more optimistic and continue to reduce my vulnerability to depression as a 53-year-old adult in 2019.

Over the past few months, I've recounted various autobiographical life experiences and written about how remembering positive memories from adolescence has benefited my psychological and physical well-being across a lifespan. (See, "Is Sugar-Coating Bad Childhood Memories a Winning Formula?", "Music, Fiction, and the Neuroscience of Active Forgetting," "Flip the Script: Turning Naysayer Put-Downs Into Rocket Fuel" and "Growth Mindset Advice: Take Your Passion and Make It Happen!")