Method: we use survey, data of the three waves of The Midlife in the United States (MIDUS), namely MIDUS 1 (n = 7,108), MIDUS 2 (n=4,963) and MIDUS 3 (n = 3,294). MIDUS is a longitudinal study involving participants above the age of 20 years. We use propensity score matching to develop treatment and control groups. Logistic regression analysis was used to identify the relationship between personality and mental health as well as change in personality and mental health.
Result: There is a significant relationship between personality and depression. Individuals were more likely to report depression in MIDUS 2 if they exhibited lower level of conscientiousness (p=0.07) and extroversion (p<0.05) and higher level of neuroticism (p<0.05) and agreeableness (p=0.06) on MIDUS 1. Similarly, individuals with lower level of conscientiousness and extroversion and higher level of neuroticism on MIDUS 2 were more likely to report depression (p<0.05) in MIDUS 3. Individuals were more likely to report depressive symptoms in MIDUS 3, if they reported lower level of extroversion (p=0.06) and higher level of neuroticism (p<0.05) in MIDUS 1.
Additionally, personality change and depression are related. After 10 years (MIDUS 1, 2 and 3 data were collected at a gap of 10 years), the neuroticism among individuals who experience mental health issue was significantly higher (p<0.05) as compared to individuals who did not experience mental health issue.
Conclusion: Personality and depression are related. Findings of the study will allow us to identify vulnerable population and improving interventions.