Sex hormones exert organizational and activational effects on human behavior. During the prenatal period, sex hormones organize the development of the brain, thereby causing permanent changes in brain morphology, neurotransmission, and behavior. Throughout life, sex hormones also activate brain function. Both of these organizational and activational effects are involved in the development and maintenance of addictive and other mental disorders.
Previous studies completed by our lab and other research teams indicate that prenatally-induced androgen effects contribute to the risk of addictive disorders and suicide. However, the direct measurement of intrauterine sex hormone concentrations as well as the long-term follow-up required to estimate disease risk is hardly feasible. Thus, in order to estimate prenatal sex hormone exposure, we use proxies such as the second-to-fourth finger length ratio (2D:4D; Kornhuber et al. 2011, 2013; Lenz et al. 2016, 2017), handedness (Bouna-Pyrrou et al. 2015), and the twin testosterone transfer model (Lenz et al. 2012).
The Psychoneuroendocrinology research group investigates and characterizes relationships between sex hormone activity and mental disorders. We are interested in both intrauterine-induced organizational and adult activational sex hormone effects as well as in their genetic and epigenetic aspects. To establish preventive strategies, we investigate environmental factors that may influence intrauterine sex hormone exposure as well as the genetic, epigenetic, and cellular mechanisms that transport these effects into adulthood and predispose individuals to mental disorders in later life. The latter project might yield novel disease predictors in the future. These goals are achieved through translational study projects completed in cooperation with Prof. Dr. med. Johannes Kornhuber and Prof. Dr. rer. nat. Christian Müller.
Women develop depression two to three times more often than men. However, men are approximately two times more likely to die from suicide than women. One reason for this paradox might be that depressed women are prone to expressing the typical symptoms associated with disease diagnosis, whereas men are more likely to display alternative depressive symptoms, such as impulsivity, reduced stress tolerance and excessive alcohol consumption. Interestingly, both men and women can develop this so-called “male depression”, which suggests that organizational and/or activational effects of sex hormones may contribute to this phenomenon.
We are currently recruiting male depressed patients and healthy control subjects for the FLIP-MD study (Finger Length in Psychiatry – Male Depression) to characterize the phenomenon of male depression and to investigate the role of intrauterine and adult sex hormone activities.
Contact: Dorothea Falke, Dr. med. Christian Weinland
Doctoral students: Lena Brückner, Magdalena Hübner, Colin Rentsch, Terezie Sedlinská
In the May 2013 publication of the DSM-5, the American Psychiatric Association presented the Internet Gaming Disorder as a research diagnosis and requested more research into its diagnostic and etiological assignment.
In an online study, we found that the pathological use of Internet games and social networks shares similarities with substance-related disorders (e.g., laterality, criteria for addiction; Bouna-Pyrrou et al. 2015). Moreover, we found lower 2D:4D values in pathological video game players than in healthy control subjects (Kornhuber et al. 2013). These results suggest that intrauterine sex hormone exposure is a risk factor for later pathological use of Internet games and social networks.
In the most recent TEGS study (The role of intrauterine Testosterone Exposure in Internet Gaming and Social network disorder), we aim to confirm our hypothesis of increased prenatal testosterone exposure in behavioral addictions using additional biomarkers.
Recruitment for this study was completed in January 2017. We are now performing serum measurements and data analysis.
Contact: Dr. med. Polyxeni Bouna-Pyrrou
Doctoral students: Birte Aufleger, Simona Braun, Manja Gattnar, Sofia Kallmayer, Helena Wagner
The NOAH study (Neurobiology of Alcoholism) confirmed that intrauterine and direct adult sex hormone exposure plays a role in the development and maintenance of alcohol dependence (Lenz et al. 2017). This project is being conducted in cooperation with Prof. Dr. med. Johannes Kornhuber and the Klinikum am Europakanal Erlangen. For the bicentric study, we recruited 200 patients and 240 control subjects between January 2013 and October 2014. We are currently investigating genetic and epigenetic factors involved in the association between prenatal sex hormone exposure and adult alcohol addiction.
Contact: PD Dr. med. Bernd Lenz
Doctoral students: Juliane Behrens, Marina Korobowa, Sarah Kubis, Katrin Mikolaiczik, Sarah Saigali, Petya Tanovska