These are the findings of an epidemiological study at the MedUni Vienna’s University Department of Psychiatry and Psychotherapy. The causes of this regular occurrence have so far only been inadequately researched. In cooperation with the departments of Psychiatry, Nuclear Medicine and Radiology at the MedUni Vienna, scientists are now trying to determine one of the causes using Positron Emission Tomography (PET).
The aim of the investigations is to determine the influence of exposure to light on the enzyme monoamine oxidase A (MAOA) which, when functioning normally, helps break down serotonin, dopamine and noradrenaline in a controlled manner. These biochemical neurotransmitters inside the human brain essentially help to transfer information between nerve cells at the synapses. All of the information is transmitted in a matter of milliseconds. After this, the neurotransmitter (serotonin, dopamine and noradrenaline) is either broken down or transported back to the nerve cell and reabsorbed.
According to Dietmar Winkler from the specialist outpatient clinic for seasonal affective disorder at the MedUni Vienna’s University Department of Psychiatry and Psychotherapy, researchers believe that this functional equilibrium is affected in patients with seasonal affective disorder and that the MAOA enzyme is excreted in higher quantities when light is scarce. This would increase the breakdown of neurotransmitter substances and reduce their activity, which in turn has a negative impact on the exchange of information at the synapses.
Positron emission tomography scans are being performed with a radioligand that is highly specific for monoamine oxidase A. It is hoped that these scans will provide information on the effects of lack of light on MAOA, with the ultimate aim of developing new ways of treating seasonal affective disorder.
Multidisciplinary collaboration at the MedUni Vienna
The current FWF Science Fund-sponsored study (“Influence of light exposure on cerebral MAO A in patients with seasonal affective disorder”) has 24 test subjects with seasonal affective disorder and 24 healthy comparison subjects. Twelve patients in each group will be given light therapy on a randomised basis for three weeks, while the other half will be treated with a placebo lamp. At the same time, the test subjects will wear portable photometers on their wrists that will measure their exposure to light. Blood samples will also be taken for DNA analysis. A PET scan will be carried out on three separate occasions: twice in winter before and after light therapy, and once in the following summer.
The study is being carried out as a multi-disciplinary collaboration between the University Department of Psychiatry and Psychotherapy (led by Siegfried Kasper, study principals: Dietmar Winkler and Rupert Lanzenberger) and the University Department of Radiology and Nuclear Medicine, Clinical Department of Nuclear Medicine (led by Marcus Hacker, study principals: Wolfgang Wadsak, Markus Mitterhauser). Patients with this condition can contact the MedUni Vienna on: +43/1/40 400 – 73 882 or by e-mail at: [email protected].
Service: Congress of the World Psychiatric Association (WPA) in Vienna
The WPA Congress is being held from 27th to 30th October 2013 at the Austria Center Vienna. MedUni Vienna experts Siegfried Kasper and Rupert Lanzenberger will be among the speakers at the event. For more details and the programme, visit: www.wpaic2013.org.