2 – 9 percent of patients with severe depression take their own lives. Although antidepressants are among the most effective medications for people with severe depression, a controversy emerged as to whether these drugs – in particular selective serotonin reuptake inhibitors (SSRI) – could be related to the occurrence and intensification of suicidal thoughts. Several studies basically show a decrease in suicides during treatment with antidepressants. Nevertheless, there is evidence that a subgroup of patients making up at least 4 to 14 percent develop suicidal thoughts during the first few weeks after starting treatment or following a dose adjustment of the antidepressant: thoughts which, in spite of the depression, did not occur before then. “While there is no study that is able to clearly prove such a correlation, there is nonetheless robust evidence that about one in ten patients is affected by this phenomenon”, explains Dr. Andreas Menke from the Max Planck Institute for Psychiatry in Munich.
Black box increases suicide rate
Based on findings from a meta-study, approximately ten years ago the U.S. Food and Drug Administration ensured that a number of antidepressants be provided with a so called “black box” warning on the packaging. According to it, young patients of less than 25 years of age were particularly at increased risk of developing suicidal thoughts after taking these antidepressants. European authorities followed suit and uncertainty grew among the patients. However the well-intentioned approach caused a different outcome to that planned. “Using the warning exactly the opposite was achieved: as a result, the numbers of prescription of antidepressants decreased, after which more suicides entailed”, says Dr. Menke. According to studies from the years 2007 and 2008, the decline in antidepressants in the treatment of major depression affected not only children and adolescents, but also adults. Since then, the trend has continued – without adequate alternative treatment options.
Suicidal thoughts apparently linked to antidepressants
Suicidal thoughts indeed even occur among patients with severe depression who are treated using psychotherapy; a meta-analysis of approximately 14,500 patients, however, showed that this occurs significantly more often among patients who are treated using antidepressant. Despite sincere efforts there is still no possibility of forecasting which patients will be affected by this phenomenon. Dr. Menke and his colleagues already three years ago sought in a study to find molecular markers in the genome of patients with major depression, which could allow a prediction for the development of suicidal thoughts among those treated with antidepressants. “A reliable prediction would give doctors and patients more certainty in therapy”, explains the doctor as its benefits. “Depending on the severity of the condition one could prefer to employ psychotherapeutic treatment instead of of drug therapy, or better monitor the patient as an in-patient”, he adds. Sedatives could also be used to counteract suicidal thoughts.
90 percent of cases correctly classified
And the scientists were successful. Overall, they found 79 genetic markers that were significantly associated with patients who had increased susceptibility to suicidal thoughts when just starting drug therapy. “In another independent study, we were able to classify about 90 percent of all cases into the right risk status group”, says Dr. Menke. For these markers an industrial partner in the USA will now develop a blood test which will be distributed to a number of psychiatrists. These will again check the reliability of the test in a prospective study on their patients. Should this last test be equally successful, the industrial partner of the Max Planck Institute of Psychiatry aims to get FDA approval. Dr. Menke adds: “Our partners have also licensed the European patent, so we assume that the European market will follow”.