If left untreated and uncontrolled, high blood pressure can cause serious health problems, such as heart attack, stroke or kidney failure. But findings from a recent study published in the journal Hypertension show that medications for this illness may also dramatically increase a person’s risk of eventually developing depression and other mood disorders, The Washington Post reports.

For the study, researchers in Scotland reviewed data on almost 144,066 middle-aged and older adults across a five-year span. Among those included in the study were 32,130 people being treated with one of four types of drugs currently used to treat high blood pressure: beta blockers (such as propranolol, metoprolol and atenolol), calcium channel blockers (including amlodipine, nifedipine and verapamil) and angiotensin antagonists (losartan, valsartan, telmisartan).

The scientists noted that during that time period, doctors admitted 299 people to hospitals because of a mental health issue, such as depression or bipolar disorder. Researchers found that people who took a beta blocker or a calcium channel blocker were twice as likely as those taking an angiotensin antagonist to be diagnosed and hospitalized with a mood disorder. Interestingly, those who took an angiotensin antagonist were 53 percent less likely to be hospitalized for mental illness than those who took no blood pressure medication at all. 

“Mental health is under-recognized in hypertension clinical practice, and the possible impact of antihypertensive drugs on mental health is an area that physicians should be aware of and consider,” said Sandosh Padmanabhan, MD, PhD, a professor at the Institute of Cardiovascular and Medical Sciences at the University of Glasgow and a study author. 

Researchers cautioned that since study data evaluated only severe cases of mood disorders among patients requiring hospitalization, the findings are limited. More studies must be conducted to assess the potential effect blood pressure drugs might have on milder cases of mental illness.

In addition, scientists also concluded that certain hypertension medications, such as those in the angiotensin antagonist class, might be useful as off-label, or repurposed treatments for depression and bipolar disorder if the results of independent studies are validated. 

In the meantime, click here to learn more about some surprising facts about high blood pressure.