High blood pressure is a leading cardiovascular disease risk factor and is considered to be associated with psychological factors. However, the causal relationships between blood pressure and anxiety, depressive symptoms, neuroticism, and subjective wellbeing are unclear.
A new study assessed the genetic relationships between blood pressure and anxiety, depressive symptoms, neuroticism, and subjective well-being. Scientists used a technique called Mendelian randomization. To gain genetic evidence for a causative association and minimize the biases present in observational studies, this method uses genetic variants as a proxy for a specific risk factor—in this case, blood pressure.
Over 1000 genetic single nucleotide polymorphisms, or SNPs for short, have been linked to blood pressure, accounting for between 30 and 60 percent of it. SNPs aid in predicting an individual’s response to specific medications, vulnerability to environmental influences, and the likelihood of developing diseases.
The scientists used DNA from blood samples taken from persons with primarily European ancestry from 8 large-scale study databases (genome-wide association studies).
They used Mendelian randomization to compare four psychological states—anxiety (463,010 samples), depressive symptoms (180,866), neuroticism (170,911), and subjective wellbeing—with four blood pressure traits—systolic blood pressure (736,650 samples), diastolic blood pressure (736,650 samples), and high blood pressure (above 140/90 mm Hg) (298,420).
The analysis revealed that high and diastolic blood pressure had significant causal effects on neuroticism but not anxiety, depressive symptoms, or subjective well-being.
Only diastolic blood pressure, based on 1074 SNPs, was strongly linked with neuroticism (above 90%) after numerous tests were taken into account.
The scientists are aware that their findings have some limitations. For instance, pleiotropy—where one gene might affect numerous traits—could not be entirely disregarded. Additionally, it’s possible that the findings only apply to persons with European ancestry.
“Individuals with neuroticism can be sensitive to the criticism of others, are often self-critical, and easily develop anxiety, anger, worry, hostility, self-consciousness, and depression.”
“Neuroticism is viewed as a key causative factor for anxiety and mood disorders. Individuals with neuroticism more frequently experience high mental stress, which can lead to elevated [blood pressure] and cardiovascular diseases.”