Research found that the neurotic personality trait is extremely likely to be caused by diastolic Blood Pressure, which is the lower of the two numbers in a blood pressure reading.
And maintaining control over it can aid in reducing neurotic tendencies, anxiety, and heart and circulation disorders, the researchers said.
The psychological conditions of anxiety, depression, and neuroticism are thought to be linked to high blood pressure, a major risk factor for cardiovascular disease. Neuroticism is a personality trait characterized by a propensity to experience negative emotions, such as anxiety and depression.
But it's not totally obvious which causes which.
The researchers employed a method known as Mendelian randomization to attempt to answer this question. This method reduces the biases present in observational studies by obtaining genetic evidence supporting a causal relationship by using genetic variants as proxies for a specific risk factor, in this case, blood pressure.
Over 1,000 genetic single nucleotide polymorphisms, or SNPs for short, are linked to blood pressure, accounting for 30% to 60% of the variance in blood pressure. SNPs aid in predicting a person's susceptibility to environmental factors, their response to specific medications, and their risk of contracting diseases.
The researchers 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 the four characteristics of blood pressure—systolic blood pressure (736,650 samples), Diastolic Blood Pressure (736,650 samples), pulse pressure (systolic blood pressure minus diastolic blood pressure; 736,650 samples), and high blood pressure (above 140/90 mm Hg; 463,010 samples)—with the four psychological states—anxiety (463,010 samples), depressive symptoms (180, (298,420).
Analyses showed that hypertension and diastolic blood pressure significantly contributed to neuroticism, but not to anxiety, depressive symptoms, or subjective well-being.
But after adjusting for various tests, only diastolic blood pressure (based on 1,074 SNPs) was significantly associated with neuroticism (over 90%).
The researchers are aware of some limitations in their research. For instance, pleiotropy, in which one gene affects several traits, could not be completely excluded. Beyond those with European ancestry, the findings might not be more broadly applicable.
However, they note that because blood pressure connects the brain and the heart, it may facilitate the growth of personality traits.
People with neuroticism are frequently critical of themselves, can be sensitive to criticism from others, and can easily experience anxiety, worry, anger, hostility, self-consciousness, and depression.
"Anxiety and mood disorders are thought to have neuroticism as a major contributing factor. High mental stress, which can result in elevated [blood pressure] and cardiovascular diseases, is more frequently experienced by people who are neurotic "they write.
The reduction of neuroticism, neuroticism-inducing mood disorders, and cardiovascular diseases can all be benefited from appropriate blood pressure monitoring and management.
