There are calls for “at least a million more Britons” to be put on antidepressants. This is odd because Britain’s National Health Service already “prescribed a record number of antidepressants” in 2016.
That represented “a massive 108.5% increase on the 31 [million] antidepressants which pharmacies dispensed in 2006.” In the States, one estimate is that 12% are already on these drugs.
Still, the clarion for ever more drugs was signaled after the results from a new statistical analysis were announced.
The study was “Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major depressive disorder: a systematic review and network meta-analysis.” It was led by Andrea Cipriani and published in The Lancet.
Do antidepressants alleviate or ameliorate the suffering caused by acute major depressive disorder? In some cases, the analysis says the answer appears to be yes. Which means that in some cases, the answer appears to be no. This is another way of saying that antidepressants don’t always work, or do not work for all people all of the time.
And that means that, at least for some, placebos are as “effective” as the active chemicals in antidepressants. The authors admit “Depressive symptoms tend to spontaneously improve over time and this phenomenon contributes to the high percentage of placebo responders in antidepressant trials.”
Placebos, it should go without saying, do not carry any risk of side effects. Actual drugs do; about which, more in a moment.
Caution Over the Results
Now this was not an original study, but a re-look at old studies called a “meta-analysis.” As a statistician, I only often half-jokingly say that meta-analyses are conducted to “prove” what individual studies could not. If the results from individual researches were clear and robust, meta-analyses would hardly be needed. On the other hand, a meta-analysis can provide a vantage individual studies cannot. The limitations of the method must be kept in mind.
Only studies that treated acute depression were examined here. What about side-effects? Cipriani cautioned “that some of the adverse effects of antidepressants occur over a prolonged period, meaning that positive results need to be taken with great caution, because the trials in this network meta-analysis were of short duration.”
The result of the meta-analysis indicate antidepressant effectiveness is not strong, classed as medium to small effect sizes. The authors warn “Given the modest effect sizes, non-response to antidepressants will occur.” Meaning not all who are given drugs will react to them.
Now the study’s reported statistical measures are highly specialized and take definite meaning only inside a mathematical system. The details are too technical to go into, but naive use of reported measures can exaggerate effectiveness.
If you’re not taking so many pills you can’t see straight, click here to read the rest.