New research finds that people recovering from a major depressive episode take longer to process negative information than positive data compared to people with no history of depression. This cognitive trend may increase their risk of relapse. The study, a meta-analysis of multiple studies, concluded that focusing solely on reducing negative information processing may not be effective in preventing relapse. Instead, strategies that enhance positive information processing may be beneficial.
One study suggests that focusing on the positives may be just as important as reducing the negatives when it comes to preventing relapse.
Compared with people who have never experienced a depressive episode, people who experience a major depressive episode tend to spend more time dwelling on negative information and less time focusing on the positive. This pattern may put them at risk for relapse, according to research published by the American Psychological Association.
"Our findings indicate that people with a history of depression spend more time processing negative information (such as sad faces) than positive information (such as happy faces), and that this difference is greater compared with healthy people without a history of depression," said lead author Alainna Wen, Ph.D., a postdoctoral scholar at the UCLA Center for Anxiety and Depression Research. "Because more negative thoughts and emotions and less positive thoughts and emotions are characteristic of depression, this may mean that these people are at greater risk of developing another episode of depression."
The study was published in the Journal of Psychopathology and Clinical Sciences.
Incidence and impact of major depressive disorder
Major depressive disorder is one of the most common mental illnesses in the United States. According to the National Institute of Mental Health, approximately 21 million U.S. adults reported at least one episode of major depression in 2020 (8.4% of the U.S. population). Major depressive disorder is defined as at least two weeks of depressed mood or loss of interest or enjoyment in daily activities. Major depressive disorder interferes with or limits a person's ability to perform major life activities.
Although the treatment methods for depression are very mature, according to Wen Jiabao, the recurrence rate of major depression is still high. More than 50% of people with a first major depressive episode will have another episode at a later date, often within two years of recovery. Therefore, we need a deeper understanding of the risk factors involved in major depressive disorder to improve treatment and prevent relapse.
Research methods and results
In this paper, the researchers conducted a meta-analysis of 44 studies involving 2,081 participants with a history of major depressive disorder and 2,285 healthy controls. All studies examined participants' reaction times to negative, positive, or neutral stimuli. In some conditions, participants were shown a happy, sad, or neutral face and asked to press a different button for each. In other cases, participants responded to positive, negative, or neutral words.
Healthy participants as a group responded more quickly to emotional and non-emotional stimuli than participants with a history of depression, regardless of whether the stimuli were positive, neutral or negative. However, compared with controls, participants who had experienced major depression spent more time processing negative emotional stimuli than positive stimuli. Although there was a significant difference in the time spent processing positive versus negative emotional stimuli between healthy controls and those in remission from major depressive disorder, this difference was not evident when comparing the time spent processing negative versus neutral stimuli or the time spent processing positive versus neutral stimuli.
The findings suggest that patients with recurrent major depression not only have less control over the information they process than healthy people, they also show a greater tendency to focus on negative information rather than positive or neutral information.
"The current findings have important implications for the treatment of depression," Wen said. "Focusing solely on reducing the processing of negative information may not be enough to prevent depression relapse. Instead, patients may also benefit from strategies that increase the processing of positive information."