L-dopa medication could be helpful in the treatment of phobias and post-traumatic stress disorder

09.07.2014 - (idw) Johannes Gutenberg-Universitt Mainz

Scientists at Mainz and Innsbruck explore new treatment approach to overcome fear A drug used to treat Parkinson's disease could also help people with phobias or post-traumatic stress disorder (PTSD). Scientists of the Translational Neurosciences (FTN) Research Center at Johannes Gutenberg University Mainz (JGU) are currently exploring the effects of psychotherapy to extinguish fears in combination with L-dopa. This drug does not only help movement disorders, but might also be used to override negative memories.

Professor Raffael Kalisch, head of the Neuroimaging Center (NIC) of the JGU Translational Neurosciences Research Center, and his collaborators at the University of Innsbruck are conducting research in mice and in humans into the psychological and neurobiological mechanisms of anxiety and fear. "Fear reactions are essential to health and survival, but the memories of angst-inducing situations may cause long-term anxiety or phobias," explained Kalisch. In psychotherapy, the 'fear extinction' method is used in exposing people to a threat but without the adverse consequences. Latest research has proven that extinguishing fear also predicts mental health after trauma, suggesting extinction may be an important resilience mechanism.

Fear extinction involves a person being presented with a neutral stimulus, such as a circle on a screen, together with a painful sensation. Soon the person predicts pain in response to the circle on the screen and fear becomes conditioned. Then the person is shown the circle again, but this time without the painful stimulus, so that the person can disassociate the two factors. A person who is afraid of spiders, for example, will in psychotherapy be confronted with spiders in a way that reassures them that the spider is harmless.

In another research program, Belgian scientists tested the ability to extinguish fear in soldiers later deployed to a war zone and found differences in the soldiers' resilience to traumatic memories. Some experienced post-traumatic stress symptoms following their deployment, whereas those who were able to extinguish fear in the laboratory maintained a good state of mental health. "If you are mentally flexible enough to change the associations that your mind has created, you might be better able to avoid lasting damage," explained Kalisch. In cooperation with other scientists, Kalisch has found first evidence that this process of changing negative associations might involve the brain's systems for reward and pleasure and depend on release of the neurotransmitter dopamine that helps control them.

Abstract Reference R10221: Fear extinction as a key human resilience mechanism: dopaminergic contributions. Symposia S30: Ramping up resilience: from (epi) genetics, to optogenetics and imaging

Single dose of L-dopa makes extinction memories context-independent and prevents the return of fear. J Haaker, S Gaburro, A Sah, N Gartmann, TB Lonsdorf, K Meier, N Singewald, H-C Pape, F Morellini, R Kalisch. PNAS Plus - Biological Sciences - Psychological and Cognitive Sciences. 2013; 110 (26): E2428-36. DOI: 10.1073/pnas.1303061110

Empirical support for an involvement of the mesostriatal dopamine system in human fear extinction. K A Raczka, A Reif; J Deckert, N Gartmann, M-L Mechias, M Pessiglione, R Kalisch. Translational Psychiatry. 2011; 1: e12.

Contact Professor Raffael Kalisch Neuroimaging Center (NIC) at the Research Center Translational Neurosciences (FTN) Johannes Gutenberg University Mainz phone +49 6131 17-4588 e-mail: rkalisch@uni-mainz.de http://www.ftn.nic.uni-mainz.de/en/raffael-kalisch Weitere Informationen:http://www.uni-mainz.de/presse/17457_ENG_HTML.php - press release

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L-dopa medication could be helpful in the treatment of phobias and post-traumatic stress disorder