Summary: New research indicates that detailed personality assessments may help tailor treatment for people with bipolar disorder by identifying who is more likely to experience recurrent depression or face difficulties in daily functioning. Analyzing data from more than 2,500 people across two long-term cohorts, researchers identified combinations of personality traits—referred to as personality styles—that either increase or decrease long-term mental health risk.
High neuroticism consistently emerged as a significant risk marker for repeat depressive episodes and poorer daily functioning, while low neuroticism and more balanced trait profiles tended to be protective. The findings challenge the idea that personality is entirely fixed and support the possibility that certain traits can be modified through therapy or coaching to improve outcomes for people with bipolar disorder.
Key facts:
- Predictive styles: Specific combinations of personality traits forecast the likelihood of future depressive episodes.
- Modifiable traits: Traits once thought immutable may be improved through targeted psychotherapy or behavioral interventions.
- Personalized care: Personality assessment could inform individualized treatment planning for bipolar disorder.
Source: University of Michigan
Personalized treatment is increasingly common for illnesses such as cancer and heart disease, where tests guide clinical decisions. Mental health care has lagged behind, but this new study suggests that personality testing could bring a similar level of personalization to bipolar disorder care.
Researchers from the University of Michigan’s Heinz C. Prechter Bipolar Research Program analyzed long-term data and found that particular personality styles—combinations of trait scores derived from standardized personality inventories—were associated with distinct trajectories of depression and functional outcomes. These styles were defined within individuals rather than by comparing individuals to one another, making them highly personalized markers.
A critical element in the model was the balance between protective and risk-related personality styles. In essence, the greater the number of risk-related styles relative to protective styles, the higher the likelihood of future depressive episodes and reduced life functioning.
Lead author Kelly Ryan, Ph.D., a neuropsychologist and professor in the U-M Department of Psychiatry, noted that the instruments used are commonly administered in clinical psychology settings. She emphasized that understanding an individual’s personality style profile may explain why some people with bipolar disorder are more resilient—recovering more quickly or experiencing fewer depressive episodes—while others remain more vulnerable.
Patients could use personality test results alongside clinicians to identify targets for intervention. Since research increasingly shows personality traits can be shaped through psychotherapy, coaching, or behavioral programs, clinicians may be able to help patients strengthen protective traits and reduce those that increase long-term risk.
For example, a person with a relatively low score in openness—a trait that, when present at moderate levels, appeared protective—might benefit from interventions that encourage new experiences, such as engagement with creative activities or time in nature, which could in turn support resilience.
About the study
The research team first examined data from the Prechter program, which has followed hundreds of people with bipolar disorder for more than a decade. The discovery sample included 489 participants who completed the Revised NEO Personality Inventory (NEO PI-R), a detailed 240-item personality assessment. These participants also provided repeated measures of depressive symptoms and life functioning during follow-up clinical assessments conducted every two months or every two years.
Using established scoring methods for the NEO PI-R, researchers classified each participant’s personality style based on combinations of trait scores and then tracked associations between those styles and the number of major depressive episodes as well as changes in life functioning over time. Out of 30 possible personality styles examined, some were consistently associated with higher risk of depression and poorer functioning, while others were linked to lower risk.
As expected, styles that included high neuroticism—characterized by emotional instability and negative thinking—were reliably associated with increased depression risk. Conversely, styles featuring low neuroticism were generally protective. Several styles that did not involve neuroticism also contributed to risk or protection for both depression and life functioning, with low neuroticism consistently among the most protective factors.
To validate their findings, the investigators tested the same framework on a larger sample of more than 2,000 participants from the STEP-BD trial, who had completed the shorter NEO Five-Factor Inventory (NEO-FFI). In that replication set, two-thirds of the personality styles that predicted higher depression risk in the discovery sample also predicted higher risk, and nine of the sixteen styles that appeared protective in the discovery sample retained that protective relationship. This replication strengthened confidence in the predictive value of personality styles.
Across cohorts, the ratio of risk-related to protective styles was a robust predictor: each additional risk-style relative to protective styles was associated with a measurable increase in the incident rate of depressive episodes and decline in functioning. The replicated patterns suggest clinicians could use personality-style assessment to identify patients at higher risk for adverse long-term outcomes.
Funding and authorship
The study was funded by the Heinz C. Prechter Bipolar Research Fund and the Richard Tam Foundation. In addition to Kelly Ryan, the authors include Anastasia K. Yocum, Yuhua Zhang, Peisong Han, David F. Marshall, Paul T. Costa, Sarah H. Sperry, Takakuni Suzuki, Melvin G. McInnis, and Sebastian Zöllner. Paul T. Costa co-developed both personality tests used in the research along with Robert McCrae; the tests are published by PAR and are available for licensed use.
About this personality and bipolar disorder research news
Author: Kara Gavin
Source: University of Michigan
Contact: Kara Gavin – University of Michigan
Image: Image credited to Neuroscience News
Original research: Open access. “Predictive evidence for the impact of personality styles on depression and functioning in two bipolar disorder cohorts” by Kelly Ryan et al., Journal of Affective Disorders.
Abstract
Predictive evidence for the impact of personality styles on depression and functioning in two bipolar disorder cohorts
Identifying replicable predictors of illness course in bipolar disorder is challenging. Personality traits, especially Neuroticism, are promising candidate predictors, but most models overlook the combined effects of multiple traits. This study assessed whether personality style combinations enhance prediction of symptoms and functioning over time across two longitudinal cohorts. In a discovery sample of 489 and a replication sample of 2,072 individuals with bipolar disorder, personality styles measured by the NEO PI-R and NEO-FFI predicted depression and functioning over as many as 14 years.
Considering all possible personality style combinations, the ratio of risk-related to protective styles was associated with increases in incident rates for depression and for poor life functioning. These patterns replicated in the independent STEP-BD dataset, supporting the clinical utility of assessing combined personality traits to identify individuals at higher risk for poorer outcomes. The authors recommend evaluating personality styles when planning long-term care and designing interventions for bipolar disorder.