In current diagnostic systems, schizophrenia and bipolar disorder are still conceptualized as distinct categorical entities. Recently, both clinical and genomic evidence have challenged this Kraepelinian dichotomy. There are only few longitudinal studies addressing potential overlaps between these conditions. Here, we present design and first results of the PsyCourse study (N = 891 individuals at baseline), an ongoing transdiagnostic study of the affective-to-psychotic continuum that combines longitudinal deep phenotyping and dimensional assessment of psychopathology with an extensive collection of biomaterial. To provide an initial characterization of the PsyCourse study sample, we compare two broad diagnostic groups defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) classification system, that is, predominantly affective (n = 367 individuals) versus predominantly psychotic disorders (n = 524 individuals). Depressive, manic, and psychotic symptoms as well as global functioning over time were contrasted using linear mixed models. Furthermore, we explored the effects of polygenic risk scores for schizophrenia on diagnostic group membership and addressed their effects on nonparticipation in follow-up visits. While phenotypic results confirmed expected differences in current psychotic symptoms and global functioning, both manic and depressive symptoms did not vary between both groups after correction for multiple testing. Polygenic risk scores for schizophrenia significantly explained part of the variability of diagnostic group. The PsyCourse study presents a unique resource to research the complex relationships of psychopathology and biology in severe mental disorders not confined to traditional diagnostic boundaries and is open for collaborations.

In clinical practice and in research, there is an ongoing debate on how to return incidental and secondary findings of genetic tests to patients and research participants. Previous investigations have found that most of the people most of the time are in favor of full disclosure of results. Yet, the option to reject disclosure, based on the so-called right not to know, can be valuable especially for some vulnerable subgroups of recipients. In the present study we investigated variations in informational preferences in the context of genetic testing in a large and diverse German sample. This survey examined health care professionals, patients, participants of genetic counseling sessions and members of the general population (N = 518). Survey participants were assessed regarding their openness to learning about findings under various hypothetical scenarios, as well as their attitudes about the doctor-patient-relationship in a disclosure situation and about informational transfer to third parties. While the majority of participants wanted to learn about their findings, the extent of support of disclosure varied with features of the hypothetical diagnostic scenarios (e.g., controllability of disease; abstract vs. concrete scenario description) and demographic characteristics of the subjects. For example, subjects with higher levels of education were more selective with regards to the kind of information they want to receive than those with lower levels of education. We discuss implications of these findings for the debate about the right not to know and for the clinical practice of informed consent procedures.

The current study is the largest conducted so far to investigate the association between the cumulative BD and SCZ polygenic risk and AAO in BD patients. The reported negative results suggest that such a polygenic influence, if there is any, is not large, and highlight the importance of conducting further, larger scale studies to obtain more information on the genetic architecture of this clinically relevant phenotype.

The progress of medical genetics leads to a significant increase in genetic knowledge and a vast expansion of genetic diagnostics. However, it is still unknown how these changes will be integrated into medical practice and how they will change patients' and healthy persons' perception and evaluation of genetic diagnoses and genetic knowledge. Therefore, we carried out a comprehensive questionnaire survey with more than 500 patients, clients seeking genetic counseling, health care staff, and healthy persons (N = 523). The questionnaire survey covered detailed questions on the value of genetic diagnoses for the different groups of study participants, the right to know or not to know genetic diagnoses, possible differences between genetic and other medical diagnoses, and the practical use and implications of genetic knowledge with a special focus on hereditary neuropsychiatric diseases. A huge majority of the participants (90.7%) stated to have a right to learn every aspect of her or his genetic make-up. Similarly, study participants showed high interest (81.8%) in incidental health care findings-independent of whether the diseases are treatable or not. One can derive from the data outcome that study participants did not follow the implications of a "genetic exceptionalism" and often considered genetic findings as equivalent in relation to other medical diagnoses.

In current diagnostic systems, schizophrenia and bipolar disorder are still conceptualized as distinct categorical entities. Recently, both clinical and genetic evidence have challenged this Kraepelinian dichotomy. There are only few longitudinal studies addressing the potential overlaps between these conditions. Here, we present design and first results of the PsyCourse study, an ongoing transdiagnostic study of the affective-to-psychotic continuum that combines longitudinal deep phenotyping and dimensional assessment of psychopathology with an extensive collection of biomaterial. Within the DSM-IV framework, we compare two broad diagnostic groups: one consisting of predominantly affective and one of predominantly psychotic disorders. Depressive, manic, and psychotic symptoms as well as global functioning over time were analyzed. Furthermore, we explore the effects of polygenic risk scores for schizophrenia on diagnostic group membership and address their effects on non-participation in follow-up visits. While phenotypic results show differences in both current psychotic and manic symptoms, depressive symptoms did not vary between both groups. Polygenic risk scores for schizophrenia significantly explained part of the variability of the diagnostic group. Furthermore, there was a trend that a higher polygenic loading for schizophrenia was associated with attrition. Because of its unique properties, the PsyCourse study presents a prime resource for the interrogation of complex genotype-phenotype relationships.