Commonly prescribed anti-depressants appear to be doing patients more harm than good, say researchers who have published a paper examining the impact of the medications on the entire body.
"We need to be much more cautious about the widespread use of these drugs," says Paul Andrews, an evolutionary biologist at McMaster University and lead author of the article, published today in the online journal Frontiers in Psychology.
"It's important because millions of people are prescribed anti-depressants each year, and the conventional wisdom about these drugs is that they're safe and effective."
Andrews and his colleagues examined previous patient studies into the effects of anti-depressants and determined that the benefits of most anti-depressants, even taken at their best, compare poorly to the risks, which include premature death in elderly patients.
Anti-depressants are designed to relieve the symptoms of depression by increasing the levels of serotonin in the brain, where it regulates mood. The vast majority of serotonin that the body produces, though, is used for other purposes, including digestion, forming blood clots at wound sites, reproduction and development.
What the researchers found is that anti-depressants have negative health effects on all processes normally regulated by serotonin.
The findings include these elevated risks:
- developmental problems in infants
- problems with sexual stimulation and function and sperm development in adults
- digestive problems such as diarrhea, constipation, indigestion and bloating
- abnormal bleeding and stroke in the elderly
The authors reviewed three recent studies showing that elderly anti-depressant users are more likely to die than non-users, even after taking other important variables into account. The higher death rates indicate that the overall effect of these drugs on the body is more harmful than beneficial.
"Serotonin is an ancient chemical. It's intimately regulating many different processes, and when you interfere with these things you can expect, from an evolutionary perspective, that it's going to cause some harm," Andrews says.