Psychiatric drugs are not inferior to other drugs, review concludesBMJ 2012; 344 doi: http://dx.doi.org/10.1136/bmj.e856 (Published 03 February 2012) Cite this as: BMJ 2012;344:e856
A review of meta-analyses has concluded that psychiatric drugs are, in general, as effective as drugs used in other medical specialties.
Researchers from the Technische Universität München in Germany said they carried out the review because there is a deep mistrust of psychiatry fostered by reports indicating that psychotropic drug efficacy is small.
The study, published in the British Journal of Psychiatry (2012;200:97-106), included 94 meta-analyses of 48 drugs in 20 medical diseases and 33 meta-analyses of 16 drugs in eight psychiatric disorders. The researchers chose reviews of classes of drugs rather than single drugs and excluded meta-analyses of subgroups such as older people. They also chose the most recent reviews.
For each meta-analysis the researchers looked at the absolute risk difference between the drug and placebo and the relative risk reduction and calculated an overall effect size. An effect size of 0.2 is considered significant but low and an effect size of 0.8 or above is considered high.
Some general medicine drugs had very high effect sizes—for example, 2.27 for interferon to treat hepatitis C and 1.39 for proton pump inhibitors to treat reflux oesophagitis. But some commonly used general medicine drugs had much smaller effects. For example, for the secondary prevention of cardiovascular events aspirin had an effect size of 0.12 and statins an effect size of 0.15.
Psychiatric drugs were overall found to be in the same range as the general medicine drugs. Antidepressants used as maintenance treatment to prevent patients having a relapse of major depressive disorder had an effect size of 0.64 and antipsychotics to prevent relapse in schizophrenia had an effect size of 0.92. Treatment with methylphenidate for attention deficit hyperactivity disorder had an effect size of 0.78.
Lead study author Stefan Leucht said: “There is a deep mistrust of psychiatry, fostered by reports suggesting that the efficacy of psychiatric drugs is very small. Psychiatrists, patients, carers, and the media are often unsettled by these findings, and some may think that psychiatric medication is not worth the bother.”
He added: “There are reasons why people should be critical about psychiatric drug treatment, such as a lack of diagnostic tests, commercial conflict of interest, unclear mechanism of drug action and side-effects. But our study shows that the psychiatric drugs were not generally inferior to those used in other medical specialties, and the effectiveness of psychiatric drugs is supported by randomised controlled trials.”
The study has a number of limitations. Even though the authors made an effort to be systematic it is not a systematic review. The researchers selected the diseases and the meta-analyses they included. The study also did not address side effects, which are a serious problem with many psychotropic drugs.
But is the review like comparing apples and pears? The authors admit that any comparison of different outcomes in different diseases can only serve the purpose of a qualitative perspective. Any improvement by a drug over placebo “has to be viewed in the context of the disease’s seriousness, suffering induced, natural course, duration, outcomes, adverse events and societal values.”
Peter Byrne, consultant liaison psychiatrist and director of public education at the Royal College of Psychiatrists, said the study was very welcome. “It’s a substantial study that puts psychiatry well into the mainstream of medical treatment. There is a folk wisdom that psychiatric drugs are not as effective as other drugs. Medical students see that the placebo effects for psychiatric drugs are relatively high so they assume that they are no better than placebo. This study shows that psychiatric drugs are just as effective as drugs for other medical conditions,” he told the BMJ.
Cite this as: BMJ 2012;344:e856