SHANGHAI, China — Could hypertension change your personality? Having high blood pressure may cause someone to feel more neurotic, a recent study finds.
Researchers in China say the most important indicator is diastolic blood pressure — the lower of the two numbers when measuring a person’s blood pressure. Beyond heart problems, the findings give another reason to control blood pressure.
People with high blood pressure are at high risk for heart disease, but it’s been unclear how the condition affects a person’s mental state. Past research has pointed to a possible link between high blood pressure and anxiety, depression, and neuroticism. The team explains that neuroticism is a personality trait where people are highly self-critical and are prone to experiencing anger, anxiety, irritability, and emotional instability.
In the current study, the authors used a technique called Mendelian randomization. This involves measuring genetic variants for a risk factor. In this case, that was blood pressure. They looked for any genetic evidence that could explain its relationship with neuroticism.
Genetic factors determine 30% and 60% of a person’s blood pressure readings
There are over 1,000 genetic single nucleotide polymorphisms (SNP) associated with it. SNPs are helpful to scientists because they can predict a person’s likely response to drugs, environmental factors, and risk of developing diseases.
The genetic information was compiled from eight large study datasets where researchers took DNA from blood samples of participants. Most people were of European ancestry. The team then applied Mendelian randomization to four traits of blood pressure — systolic blood pressure, diastolic blood pressure, pulse pressure, and high blood pressure. They then compared it to four cognitive symptoms — anxiety, depression, neuroticism, and a person’s subjective well-being.
Diastolic blood pressure displayed a strong association with neuroticism. Based on 1,079 SNPs, there was a 90-percent link between the two. One explanation the study authors propose is that blood pressure has a connection to the brain and the heart so alterations in it could fuel the development of certain personality traits.
“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,” the researchers write in a media release.
There was no link between blood pressure and anxiety, depression, or subjective well-being.
The team notes there were some limitations to the study that could affect the interpretation of the results. First, the authors were not able to exclude pleiotropy, which is when one gene can affect several traits. Since most participants were of European descent, the association may not be the same for those of other races and ethnicities.
The study is published in the journal General Psychiatry.