Recently, store running into a dentist acquaintance unexpectedly turned into a run-in on the subject of diagnosing and treating depression. The dentist strongly believes that antidepressant medication is systematically overprescribed by physicians and that doctors should be held accountable for their behaviour.
On the one hand, medical I understand where the dentist is coming from. He gathers information from his patients about their current medications, sick so he has insight into physicians’ prescribing patterns.
At the same time, I told him that I though he has a distorted and dogmatic view that conflicts with what we know.
The counterargument goes as follows.
Depression is a common illness. Current data from the National Institute of Mental Health show that at any given point in time, about 7% of the population –1 in 15 adults – is suffering an episode of depression. For a dentist seeing 30 patients a day, that means that on average two of those patients might be taking antidepressants.
Though we have a good idea of the proportion of people who are depressed we aren’t as good at knowing precisely who is and who isn’t. That’s because depression is difficult to reliably diagnose. The American Psychiatric Association criteria require asking the patient questions that don’t necessarily lead to yes or no answers. And despite attempts to develop more “objective” measurements of depression, we have failed to find brain imaging changes that are specific to depression and there is still no blood test that can confirm any mood disorder.
Furthermore, the standardized questions are good but they still lack accuracy. That means that the dentist is partly right: we inappropriately prescribe antidepressants in some cases because we mistakenly label some people as having depression when they in fact don’t. While that can be due to a doctor failing to properly assess the patient, it’s more likely the result of the problems with the diagnostic tools.
What the dentist didn’t want to acknowledge is that the flaws in those diagnostic tools also lead to underdiagnosing depression. In fact, we have as much evidence of undertreatment of depression as we do of overprescribing. That’s at least partly due to the unfortunate but continuing social stigma of mental illness, which makes people reluctant to seek help or accept treatment (see this previous post on overcoming stigma, self-blame and hopelessness).
That said, there is enough uncertainty about the quality of the diagnostic tools that the Canadian guidelines on whether to seek out depression in patients and the US guidelines uncharacteristically differ, with Canadian guidelines finding insufficient evidence to support screening but US guidelines recommending it. The research community also continues to actively debate which of the available questionnaires is best.
But disagreements on diagnosing depression aren’t limited to the question of whether or not a person is currently depressed. The diagnosis process also classifies depressed patients according to the severity of their illness: mild, moderate or severe. Where to set the dividing line between each category and the proper treatment for a given level are the primary controversies.
The focus of the treatment debate is moderate depression. While there is general agreement that mild depression should be treated without antidepressants and that severe depression requires drugs and often hospitalization, the evidence on the benefit of antidepressant medication for moderate depression is variable. That was the crux of the dentist’s accusations against physicians: we wrongly prescribe antidepressants in patients who are “only” moderately depressed.
Because my debate with the dentist ended there I didn’t provide him with my additional arguments against his perspective.
First, a health professional who doesn’t experience people confiding their feelings and emotions can easily underestimate the impact of depression on patients. Moderate depression creates real impairment to day-to-day function and quality of life. Thus, it’s worth treating.
The dentist could rightly respond that just because a patient would benefit from treatment doesn’t mean that the treatment should be antidepressants; evidence shows that counselling is as effective as medication (see this post on treating depression). While that’s inarguably true, the fact remains that patients prefer medication to talk therapy: it’s less time-consuming, less expensive and doesn’t involve the need to talk about one’s feelings.
Of course, antidepressants, like all other drugs, cause side effects. However, they don’t do so at an alarming rate and dangerous side effects are very rare. And the risk of side effects is included in the risk-benefit analysis that leads to recommendations to use the medications in the first place.
Are there some people taking antidepressants who shouldn’t be? Definitely. But there are also many people who could benefit from antidepressant medication who haven’t sought help or who have been assessed as having a depressive episode that’s too mild for drug therapy.
My bottom line message to the dentist: if patients are moderately depressed and after consultation with their doctor they want to see whether they can benefit from antidepressants, it certainly isn’t inappropriate for the physician to prescribe them.