Major depression is currently the leading cause of disability in the industrialized world. Roughly 10% of Canadians will experience a clinically significant episode of depression at some point in their lives. In the Greater Toronto Area alone, more than 300,000 people (around 5-6% of the population) would meet the formal diagnostic criteria for major depression during any given year.
With major depression being so common and so disabling, antidepressants are among the most widely prescribed of all classes of medications today. Many people find antidepressant medication to be effective in lifting their mood, and restoring their lives to a healthy level of function. The convenience of medications is also hard to beat: compared to many other treatments, they are relatively inexpensive, require little time commitment, and have relatively minor side effects for many people.
Unfortunately, more than a third of all individuals with depression cannot find a medication that helps them. Others find the side effects of medication to be intolerable. Even among those who do respond, a large proportion will relapse into illness once again. For people in these situations, other options are needed.
Psychotherapy is another effective treatment for major depression. There are several standardized forms of therapy that are known to be effective against depression, including cognitive behavioural therapy, interpersonal therapy, and mindfulness-based cognitive therapy. However, getting access to a therapist can also be difficult, or expensive. With so many millions of Canadians suffering from depression, the supply of well-trained therapists may never be large enough to provide effective one-on-one therapy to everyone who needs it.
Even for those who can find it, however, therapy is hard work. There are appointments to be kept, skills to be learned, exercises to be done, and habits to be overcome. For many people with severe depression, simply finding the energy and motivation to get out of bed can be a challenge. In this all-too-common scenario, a third kind of treatment may be helpful: direct stimulation of the brain.