This is apparent from research led by Maastricht University, that Wednesday is published in JAMA Psychiatry. In addition to a sensitivity to psychosis, the patients who are excluded from drug studies also suffer from an addiction, physical disorder or suicidal thoughts. Precisely in this more complicated group, the drugs appear to be less effective: they are more often hospitalized within a year because of a psychosis.
‘It is very painful that these kinds of drugs are tested in only 20 percent of the patients for whom they are intended,’ says Jurjen Luykx, lead author of the publication, psychiatrist and educator at GGNet and researcher at the universities of Maastricht and Utrecht. ‘It is precisely in psychiatry that there are many people who do not meet the ideal: they not only suffer from psychoses, but also from addictions or physical disorders. We say: just include that group in the studies, then you can better see what you can expect from a medicine.’
In other branches of medicine, too, there is sometimes a considerable difference between the people on whom a treatment is tested and the people who ultimately receive the treatment. This problem is known from, among other things, therapies against lung cancer and hivor at relationship Therapy.
More than one diagnosis
Nevertheless, Luykx finds the exclusion rate among psychiatric patients at 80 percent ‘remarkably high’. His statement? ‘In psychiatry it is common for people to have more than one diagnosis. More than in oncology, for example.’
For the avoidance of doubt, all this does not mean that doctors have no idea whether a drug is working for their patient. ‘Often a drug will also work for a patient who would have been excluded from a study,’ says Luykx. ‘But it is useful for psychiatrists to know what to be aware of: is it necessary to also send a patient to a discussion group, or to involve the family? You can estimate that better if you also let the more difficult group participate in the experimental phase.’
Luykx worked together with colleagues from abroad to expose the gap between test and practice. They looked at the records kept for decades for Finnish and Swedish psychiatrists: which patients they saw, which diagnosis(s) received them, and which treatment. Four out of five psychotic patients prescribed a particular drug would have been banned from studies of the same drug. That was true in Sweden as well as in Finland – and it would be no different in the Netherlands, Luykx thinks.
‘It is good that the effectiveness of medicines is being researched in the real world,’ says Toine Pieters, professor of pharmaceutical sciences at Utrecht University, who was not involved in the publication inJAMA Psychiatry. ‘Such studies are not done enough, mainly because there is little money available for them. The pharmaceutical industry prefers to focus on research with which they can bring new medicines to the market.’
Holy Grail?
Before a drug is approved, it must be tested by a treatment group, compared with a control group (which is given a fake drug). Neither doctor nor patients know who belongs to which group. If the group that received the drug is clearly doing better than the group that did not receive the drug, then the effectiveness has been demonstrated. It is common practice in this type of research to establish exclusion criteria: excessively eccentric patients should not be included, as they may skew the results.
‘At first, these kinds of studies were seen as the holy grail of medicine,’ says Toine Pieters, professor of pharmaceutical sciences. ‘But now it is increasingly being said: be careful, the effectiveness is often not the same in reality as in such a study.’ According to Pieters, pharmaceutical companies are aware of this and are now selecting a more diverse group of patients than in the past. ‘Until thirty years ago, almost only white, Caucasian men took part in these studies. The male-female distribution is now better, but a lot still needs to improve as far as ethnic diversity is concerned.’