Treating Depression with SSRI Antidepressants
The selective serotonin reuptake inhibitor (SSRI) category of drugs have been on the scene for over 20 years since it was discovered that their predecessors (MAOIs and tricyclics) worked by increasing brain chemicals such as serotonin.
Serotonin occurs naturally in several places in the body but as a neurotransmitter it is concentrated in the brain around the hypothalamus and the midbrain. These brain structures are known to regulate mood.
Serotonin has an important function in ensuring the transmission of nerve impulses between nerve cells. Mood disorders such as depression are thought to occur when the concentration of serotonin varies. SSRIs work by inhibiting nerve cells from taking up serotonin too quickly, so leaving more serotonin in the brain.
We now accept SSRI medications such as prozac, seroxat and paxil, as drugs of choice for depression. Affordability and aggressive marketing have made such drugs highly accessible. You've only got to look at the advertising on this website to see this. But how effective are they?
Over a decade ago Fisher and Greenburg reported that after 15 separate literature reviews and two large-scale meta analyses the most that might be said of the effectiveness of antidepressants was ‘modest'. More recent research has gone further. Findings reported by the Journal of the American Medical Association (Jan 6th edition) stated that, on average, true drug effects are nonexistent to negligible in patients with mild, moderate and even severe baseline symptoms. The only clinically significant effects are seen in patients with very severe symptoms.
There remains concern that the convenience of antidepressant drugs is acting to block the development of other forms of therapy, which in real terms are more effective, but take longer and cost more. If the true drug effects of antidepressants are "negligible" in most cases of depression, what is it we see in people who report feeling better or relieved when they are taken? The most obvious answer seems to be they are responding to factors beyond the chemical effects of the medication. Fisher and Greenburg touched on this very issue. They say, "administering a drug is not simply a medical (biological) act. It is, in addition, a complex social act whose effectiveness will be mediated by such factors as the patient's expectations of the drug and reactions to bodily sensations created by that drug, and the physician's friendliness and degree of personal confidence in the drug's power . . "
It seems clear we've got a long way to go before we truly understand the complex inter-relationship between possible chemical imbalance and our various mental mechanisms that collaborate in the construction of our moods.
Fisher, S & Greenburg, R.P. (1995) Prescription for Happiness? Psychology Today, 28, 32-37.
Fournier, J. C. et al (2010) Antidepressant Drug Effects and Depression Severity. Journal of the American Medical Association. Jan 6, vol 303, No 1. 47-53.