Does Low BP Cause Depression Increasing the Risk For Diabetes?

According to the Netherlands Study of Depression and Anxiety, patients with anxiety had a significantly higher mean DBP than controls (P = 0.03), although this did not significantly raise the risk for isolated diastolic hypertension. These results remained after subjects using hypertension medication were excluded.

The study authors speculate on several possible reasons that depressed patients have low blood pressure. First, these patients may be more likely to use medications that treat hypertension, although this study did not find more users of these drugs in the groups with a psychiatric diagnosis, and results were similar when antihypertensive users were excluded from the analyses.

Another explanation could be that both depression and low blood pressure have a common cause. For example, a malfunction in metabolism that increases or decreases levels of certain metabolites, hormones, or neurotransmitters may affect both depression and blood pressure, said Ms. Licht.

Perhaps the most likely explanation is that low blood pressure may actually cause depression. People with low blood pressure are often tired, cold, and dizzy and have problems with concentration — symptoms that may cause depression, she said.

She added that the association may go both ways — individuals with low blood pressure may be more likely to become depressed, and those with depression may be more likely to develop low blood pressure.

Some previous research is not in agreement with these results. In fact, some studies found a positive association between depression and high blood pressure. But Ms. Licht believes the large sample size of the current study added weight to her results, as did taking into account the use of antidepressants.

In addition, she pointed out that while other studies focused on reports of depressive symptoms, this study included patients whose psychiatric diagnosis fulfilled the Diagnostic and Statistical Manual of Mental Disorders, 4th ed (DSM-IV) criteria.