“We need to be much more cautious about the widespread use of these drugs,” Paul Andrews, an evolutionary biologist at the Hamilton university said in a release. “It is important because millions of people are prescribed antidepressants each year, and the conventional wisdom about these drugs is that they’re safe and effective.” That may indeed be the conventional wisdom, but previous studies have sounded the alarm over antidepressants and particular populations.
In 2006, a study published in the New England Journal of Medicine found that taking antidepressants during pregnancy might be associated with persistent pulmonary hypertension in newborns, which can be fatal. The study prompted Health Canada to issue an advisory, which noted that earlier research had found that use of antidepressants was associated with an increase in the risk of major birth defects.
In the latest research, published Tuesday in the journal Frontiers in Psychology, Prof. Andrews and colleagues examined previous patient studies to determine the overall effects of antidepressants on the body. Their conclusion? The risk may outweigh the benefits.
Most antidepressants work by manipulating levels of serotonin, a naturally produced chemical that regulates mood. But that’s not all serotonin does. It also plays a role in reproduction, forming blood clots at wound sites and digestion.
“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 hard,” Prof. Andrews said.
The analysis of earlier studies linked antidepressant use to higher risks of not only developmental problems in infants but also problems with sexual stimulation, function and sperm; digestive problems such as constipation, diarrhea, indigestion and bloating; and abnormal bleeding and stroke in the elderly.
As well, a handful of studies showed that elderly people who take antidepressants have higher death rates than non-users, even when accounting for other variables. Given these findings, it is time for a serious, widespread discussion about the total effects of antidepressants, not just their benefits, according to Prof. Andrews.
“The thing that’s been missing in the debates about antidepressants is an overall assessment of all these negative effects relative to their potential beneficial effects. Most of this evidence has been out there for years and nobody has been looking at this basic issue,” he said.
The field of non-drug therapies is a very exciting and rapidly expanding area in part due to the vast quantity of research studies being conducted on these treatments options. There are several kinds of non-drug therapies encompassing psychotherapies or talk therapies as well as various physical treatments including electric convulsive therapy, transcranial magnetic stimulation and the two therapies we are currently concentrating on – bright light therapy and negative ion therapy.
We know that medication is a very effective treatment for severe depression. In cases of mild and moderate depression there is a variety of options that range from medications to non-drug treatments. Research studies have shown that bright light therapy is an effective first-line treatment for seasonal depression, particularly winter depression, of any severity.
More than 50 to 60 per cent of patients with recurrent winter depression respond to bright light treatment, which uses a light box that mimics natural outdoor light without harmful UV rays. Unlike medication, bright light therapy often works in seven to 10 days and has a more tolerable profile, with fewer side effects. Therefore, it tends to be used more than medication for the treatment of seasonal depression. The timing of the bright light therapy is critical; light should be administered daily, in the morning with duration of 15 to 30 minutes.
In the 1990s, negative ions were evaluated for their stimulating qualities of the nervous system and their effects on mood. The theory of negative ion therapy arose based on the knowledge that during the winter months there are less negative ions in the atmosphere and perhaps bombarding the individual’s environment with negative ions would have a therapeutic effect on their mood.
Negative ions generally have a molecule of oxygen and an extra electron, whereas positive ions are molecules that have lost an electron. Many scientists were skeptical of this form of treatment but to their surprise negative ions have been shown to have a positive effect in winter depression. But since this is a relatively new discovery we are still studying how highly ionized environments lead to these antidepressant properties.
The antidepressant effects of bright light therapy in winter depression have been more widely studied. But we do not yet know whether bright light therapy works for all types of depression, not just winter depression. There is some very preliminary evidence that suggests light therapy can be used to treat people with all types of clinical depression. What is most intriguing is that light therapy may work very quickly, perhaps even quicker than antidepressant medication.
In terms of negative ion therapy, again the focus has been on seasonal depression, and we are exploring the idea that this treatment modality may be effective in all kinds of depression. It has yet to be tested on other types of depression. Similar to light therapy, ion therapy is a very appealing treatment because it is very safe, easy to use and well tolerated with limited side effects.
Although medications work in both seasonal and other types of depression, they are effective in only about 60 per cent of cases. We are now hypothesizing that if we can provide a combination of therapies (such as light therapy or ion therapy plus medication) this would lead to a greater improvement in treating depression. This combination of treatments may lead to improvement in a larger proportion of people, and may shorten response time. The current study is taking place in multiple centres across Canada over the next three years and if we do demonstrate that combining treatments is better than any single treatment alone then this could change the way we understand and treat depression not just in Canada but worldwide.
This study is funded by the Canadian Institutes of Health Research. Dr. Anthony Levitt is psychiatrist-in-chief and Dr. Amy Cheung is adolescent psychiatrist at Sunnybrook Health Sciences Centre in Toronto.