Australia has one of the highest rates of antidepressent use in the world; however, evidence shows their effectiveness is lower than previously thought, according to the authors of a clinical focus published in Medical Journal of Australia.
"Antidepressants are the most commonly used treatment [for depression], taken by 10% of adult Australians each day, and at a rate that has more than doubled since 2000 to be among the highest in the world," wrote Dr Christopher Davey and Professor Andrew Chanen from Orygen, the National Centre of Excellence in Youth Mental Health and the University of Melbourne.
The release of the first selective seratonin reuptake inhibitors (SSRIs) in the 1980s encouraged people to think of depression as a chemical imbalance that needed to be corrected with medication, the authors wrote.
An increasing placebo response is believed to be the key reason for falling effectiveness, with the gap between response to medications and placebo narrowing.
"The placebo response is a complicated phenomenon. In part, it is driven by a positive expectation bias, but it also illustrates the statistical concept of regression to the mean, whereby patients with depressive symptoms at baseline tend to recover over time irrespective of treatment," the authors explained.
Other treatments for depression also have only modest effects, with psychotherapies such as cognitive behavioral therapy and interpersonal psychotherapy similarly showing declining effectiveness in more recently published trials.
Although the latest evidence may have tempered the initial enthusiasm for antidepressants, they still have a role in treating depression, the authors wrote. Combining different treatments is one way to combat lowering effectiveness.
"The combination of psychotherapy and medication is more effective than either alone," the authors wrote. "All patients should be offered psychotherapy where it is available, and medication should be considered if:
- the depression is of at least moderate severity;
- psychotherapy is refused; or
- psychotherapy hasn't been effective."
Alongside these treatment strategies, the authors wrote that good eating and exercise should be recommended to help encourage a healthy mind and body.
Article: The unfulfilled promise of the antidepressant medications, Christopher G Davey and Andrew M Chanen,Medical Journal of Australia, doi: 10.5694/mja16.00194, published 16 May 2016.