Depression is the leading mental disorder in our society, with more than 300 million people having been diagnosed with it - just under 4% of the world population. The main way in which it is treated, especially in the US, is through the use of antidepressants - among which Selective Serotonin Reuptake inhibitors (SSRIs) and Trycyclic Antidepressants (TCAs) are the most commonly prescribed. Antidepressant prescriptions have tripled since 1986, but is this justified?
In 2008, a meta-analysis by Irving Kirsch revealed that antidepressants had negligible clinical significance for 85-90% of people. In all trials, subjects who were given the drug only improved by 1.8 points on the Hamilton Scale (used widely to quantify depression) compared to the control group (subjects that were not given the drug). This is well below the UK’s National Institute of Clinical Excellence’s significance value of 3.0 for a drug to be proven clinically effective.
Furthermore, the theory of chemical imbalance, suggesting that too little serotonin in the brain could be the cause of depression, paved the way for SSRIs to be developed. SSRIs work by preventing serotonin from leaving synapses too quickly in order to boost the amount taken up by neurones. Although this treatment sounds logical, there has been no direct evidence for those with depression having too little serotonin in their brain; in fact one research group found that there was no correlation between lowering serotonin levels and decreased mood.
However, it is very precarious to simply stop prescribing antidepressants. Although you could argue that psychiatrists should simply prescribe sugar pills for depression, reducing healthcare expenses due to buying antidepressants and reducing the possible side effects, it is not ethical for doctors to lie to their patients, even if acting in their best interests - and this can pave the way for more sinister interpretations. Nevertheless, informing patients that what they are being given sugar pills means that the placebo effect, which improves a person’s depression by 7.2 on the Hamilton Scale, would be lost. Thus, modern psychiatry is very much in a conundrum at the present day.
However, antidepressants are more effective than the placebo for those who have Major Depressive Disorder (a minority of depression cases). Many clinicians prescribe antidepressants in order for patients to respond better to Cognitive Behavioural Therapy (CBT). Although the science remains unclear as to how exactly they facilitate this, one study demonstrated that severely depressed patients had an 81% recovery rate when they received a combined treatment of drugs and CBT compared to 51% with CBT alone.
With this being said, it is extremely worrying that antidepressant prescription rates are inflating. Although they do play a key role in treating some depressed individuals, and are the best form of treatment we currently have, they can be unnecessary and even harmful for those who simply do not require them. As of yet, science has no clear picture of their effects and therefore they must be carefully considered in each case. Psychiatry may be facing a therapeutic problem as well as a diagnostic one.
Sources:
Baer, D. (2017). The Number Of Americans On Antidepressants Has Skyrocketed. [online] Thriveglobal.com. Available at: https://www.thriveglobal.com/stories/11909-the-number-of-americans-on-antidepressants-has-skyrocketed [Accessed 13 Nov. 2018].
Davis, J. (2014). Cracked. London: Icon Books.
Kirsch, I., Deacon, B., Huedo-Medina, T., Scoboria, A., Moore, T. and Johnson, B. (2008). Initial Severity and Antidepressant Benefits: A Meta-Analysis of Data Submitted to the Food and Drug Administration. PLoS Medicine, 5(2), p.e45.
Mojtabai, R. and Olfson, M. (2011). Proportion Of Antidepressants Prescribed Without A Psychiatric Diagnosis Is Growing. Health Affairs, 30(8), pp.1434-1442.
Ruhé, H., Mason, N. and Schene, A. (2007). Mood is indirectly related to serotonin, norepinephrine and dopamine levels in humans: a meta-analysis of monoamine depletion studies. Molecular Psychiatry, 12(4), pp.331-359.
ScienceDaily. (2015). Combining anti-depressants, therapy may be a powerful treatment option for major therapy. [online] Available at: https://www.sciencedaily.com/releases/2015/03/150311160240.htm [Accessed 9 Dec. 2018].
Sonawalla, S. and Fava, M. (2001). Severe Depression. CNS Drugs, 15(10), pp.765-776.