Is there a bidirectional relationship between stroke risk and mood disorders in older adult patients?

Introduction Research suggests that there may be a causal relationship between stroke and depression symptoms. However, the direction of this relationship remains unclear, which suggests the possibility that it is bidirectional. Indeed, some findings suggest that depression is a common occurrence post-stroke and that individuals who have a greater stroke risk are also more likely to have depression. Conversely, there is also evidence that depression may be a risk factor for stroke. In addition, although most of the literature focuses on the relationship between cardiovascular health and depression, less is known about other mood disorders, such as bipolar disorder. This cross-sectional study sought to further elucidate the direction of the association between stroke risk and mood disorders (bipolar and major depression) by testing the relationship in both directions. Methods A total of 120 older adults (31 controls, 51 depression, and 38 bipolar patients) participated in a larger longitudinal study assessing a wide range of clinical and cognitive measures in mood patients and healthy controls. For the purposes of these analyses, we only used the baseline data of the larger study. Participants completed a non-invasive battery of neuropsychological tests, mood and anxiety rating scales, clinical rating scales, and functional assessments. The battery included a stroke risk assessment using the stroke risk profile from the Framingham Heart Study. This score is based on age, systolic blood pressure, anti-hypertensive therapy, diabetes, smoking, history of myocardial infarction, angina pectoris, coronary insufficiency, intermittent claudication, or congestive heart failure, history of atrial fibrillation, and left ventricular hypertrophy. We used linear and logistic regression models to examine the bidirectional relationship between stroke risk and mood disorders. We used linear regression models to test if depression and bipolar diagnoses predicted higher stroke risk factor scores. We used logistic regression models to examine if a higher stroke risk score would be associated with an increase in the likelihood of depression and bipolar diagnoses. Results Using linear regressions, we found that individuals that had depression had a significantly higher stroke risk factor than controls, β=2.52, p=.014, 95% CI [0.52, 4.52]. We found the same results when comparing bipolar patients to controls, β=2.05, p=.046, 95% CI [0.41, 4.06]. Logistic regression revealed that the odds of depression diagnosis increased by 1.15 times with one unit increase in stroke risk factor score p=.018, 95%CI [1.02, 1.30]. The model correctly classified 67.5% of cases. Similarly, we found that the stroke risk factor score was significantly associated with a bipolar diagnosis with an estimated odds ratio of 1.14, p=.051, 95%CI [1.00, 1.30]. The model correctly classified 61.2% of cases. Conclusions Our findings suggest that there may be a bidirectional relationship between stroke risk and mood disorders (depression and bipolar disorder). However, we would need to conduct a longitudinal study to fully understand the direction and causal nature of this relationship. In addition, there may be other variables that may mediate or moderate this relationship including unhealthy behaviors, and cognitive factors that should be evaluated in future studies. This research was funded by The Rogers Family Foundation Research suggests that there may be a causal relationship between stroke and depression symptoms. However, the direction of this relationship remains unclear, which suggests the possibility that it is bidirectional. Indeed, some findings suggest that depression is a common occurrence post-stroke and that individuals who have a greater stroke risk are also more likely to have depression. Conversely, there is also evidence that depression may be a risk factor for stroke. In addition, although most of the literature focuses on the relationship between cardiovascular health and depression, less is known about other mood disorders, such as bipolar disorder. This cross-sectional study sought to further elucidate the direction of the association between stroke risk and mood disorders (bipolar and major depression) by testing the relationship in both directions. A total of 120 older adults (31 controls, 51 depression, and 38 bipolar patients) participated in a larger longitudinal study assessing a wide range of clinical and cognitive measures in mood patients and healthy controls. For the purposes of these analyses, we only used the baseline data of the larger study. Participants completed a non-invasive battery of neuropsychological tests, mood and anxiety rating scales, clinical rating scales, and functional assessments. The battery included a stroke risk assessment using the stroke risk profile from the Framingham Heart Study. This score is based on age, systolic blood pressure, anti-hypertensive therapy, diabetes, smoking, history of myocardial infarction, angina pectoris, coronary insufficiency, intermittent claudication, or congestive heart failure, history of atrial fibrillation, and left ventricular hypertrophy. We used linear and logistic regression models to examine the bidirectional relationship between stroke risk and mood disorders. We used linear regression models to test if depression and bipolar diagnoses predicted higher stroke risk factor scores. We used logistic regression models to examine if a higher stroke risk score would be associated with an increase in the likelihood of depression and bipolar diagnoses. Using linear regressions, we found that individuals that had depression had a significantly higher stroke risk factor than controls, β=2.52, p=.014, 95% CI [0.52, 4.52]. We found the same results when comparing bipolar patients to controls, β=2.05, p=.046, 95% CI [0.41, 4.06]. Logistic regression revealed that the odds of depression diagnosis increased by 1.15 times with one unit increase in stroke risk factor score p=.018, 95%CI [1.02, 1.30]. The model correctly classified 67.5% of cases. Similarly, we found that the stroke risk factor score was significantly associated with a bipolar diagnosis with an estimated odds ratio of 1.14, p=.051, 95%CI [1.00, 1.30]. The model correctly classified 61.2% of cases. Our findings suggest that there may be a bidirectional relationship between stroke risk and mood disorders (depression and bipolar disorder). However, we would need to conduct a longitudinal study to fully understand the direction and causal nature of this relationship. In addition, there may be other variables that may mediate or moderate this relationship including unhealthy behaviors, and cognitive factors that should be evaluated in future studies.