Can personality traits affect your risk of developing depression? A CAMH study provides compelling evidence that specific personality traits are connected with depression.
Published in the Journal of Personality, the recent study adds to a growing body of research by CAMH scientist Dr. Lena Quilty into the role that personality traits play in depression. Her goal is to bring personality into real-world use in health-care settings to improve treatment.
Teasing apart personality effects
The new study focused on three personality traits: withdrawal, enthusiasm and industriousness. In an earlier study, Dr. Quilty had shown that these traits are individually linked with the severity of depression symptoms.
The three personality traits are defined as:
Withdrawal: Feeling negative emotions, such as sadness and anxiety
Enthusiasm: Experiencing positive emotions, being sociable
Industriousness: Being persistent, striving toward goals
A key part of the study was examining how these traits work in combination with each other. “Personality is typically studied one trait at a time, but traits don’t occur in isolation,” says Dr. Quilty, Senior Scientist in the Campbell Family Mental Health Research Institute and the Addictions Division at CAMH, and senior author of the study. Dr. Timothy Allen, Postdoctoral Research Fellow at CAMH, is the lead author.
For the first time, the researchers also investigated how these traits interact in people diagnosed with major depression. Two groups of adults — 354 people with depression and 375 people without a mental illness — took part in the study. In addition to personality traits, depression severity was also assessed.
In both groups, the three traits combined in ways that were clearly associated with depression. In particular, people with high-risk scores on all three traits, or even just two traits, were likely to experience depression tendencies or more severe depression.
High-risk scores were:
a high level of withdrawal,
low enthusiasm, or
low industriousness.
For example, people with high withdrawal and low enthusiasm but high industriousness were at greater risk of depression tendencies or severe depression.
On the positive side, in a “best two out of three” scenario, low-risk scores on two traits protected against the effect of a high score on the third trait. For example, if a person scored high on enthusiasm and industriousness, both low-risk scores, this seemed to protect against developing greater depression tendencies or severity even when their withdrawal score was high.
“In medicine, we’ve tended to see personality as a vulnerability factor contributing to illness,” says Dr. Quilty. “Our results show that personality traits can also be protective,” says Dr. Quilty.
Translating personality into better care
Dr. Quilty’s ultimate goal is to increase the usefulness of personality to improve outcomes for people with depression.
To date, “while personality is commonly recognized as relevant, it’s not yet widely used in health care settings,” says Dr. Quilty. One reason is that earlier personality assessments tended be long, making them difficult to complete with patients in many clinical settings. Brief and robust assessments are now available, and have been shown to be effective. More importantly, however, there remains limited evidence on how to use personality measures to guide treatment.
Dr. Quilty believes that, with further research, personality traits may prove to be useful markers in making health-care decisions. While a person’s score for a personality trait may rise or fall over time, how that score ranks relative to other people will generally stay consistent over time, providing a reliable indicator of opportunities to intervene.
An opportunity may come from the best two of three finding. If a patient has a low-risk risk score on one personality trait, a future research direction may be identifying therapeutic approaches that can reduce the high-risk score on a second trait. The idea is that this may protect against developing more severe depressive symptoms or tendencies.
To begin to map out treatment directions, the researchers are studying the links between personality and treatments, specifically if personality changes after starting a treatment may indicate who will respond better to the treatment.
“Our long-term goal is to give tools that can be feasibly implemented across multiple kinds of health-care settings,” says Dr. Quilty.
In the Summer 2018 Issue of CAMH Discovers Quarterly:
