Biological correlates of hypomanic personality: genetics, sleep and brain arousal

Background: Hypomanic personality (HYP) has been suggested as a risk-factor for bipolar affective disorder (BAD). Whereas tentative data on validity of HYP in predicting BAD are available, data on biological correlates are scarce. Therefore, we associated different biological traits, which can be expected to be linked to HYP: Candidate polymorphisms were selected based on their relevance for the monoaminergic and/or circadian system or due to their former association with BAD. Additionally, sleep was assessed given its pivotal role in BAD. Finally, sleepiness and brain arousal were assessed as it was recently suggested that alterations in brain arousal regulation contribute to the development of affective disorders. Methods: HYP and sleepiness were assessed by questionnaires, sleep by both questionnaire and actigraphy, and arousal regulation by resting EEG. Subjects were selected from the Leipzig Health Care Study (LIFE). The number of subjects differed with regard to the analyzed phenotypes and phenotype-specific exclusion criteria (ranging from about 800 to more than 2000). Results & Discussion: Healthy HYP high scorers showed sleep, sleepiness and arousal patterns, which are similar to those found in BAD and associated diagnostic groups, such as ADHD. Some candidate genes were also associated with HYP. These results are in line with the arousal regulation theory of affective disorders (Hegerl & Hensch, 2014) and further contribute to the validation of the HYP scale. This publication is supported by LIFE – Leipzig Research Center for Civilization Diseases, Universität Leipzig. LIFE is funded by means of the European Union, by the European Regional Development Fund (ERDF) and by means of the Free State of Saxony within the framework of the excellence initiative.