NIMH Amish Mennonite Bipolar Genetics Study (AmBiGen)

Bipolar affective disorder is a severe, heritable condition affecting about one percent of the population. The mode of inheritance is poorly understood and probably involves multiple loci of small to moderate effect. In this project, we use genetic mapping and sequencing methods to identify genetic markers and variations that contribute to the risk of bipolar disorder. Individuals diagnosed with bipolar disorder are studied, along with their relatives. Phenotypic information obtained from clinical interviews and family history is correlated with genotypic information obtained from genetic marker and sequencing methods. The goal is to identify genes involved in bipolar disorder and related conditions so that better methods of diagnosis, treatment, and prevention can be developed.]]>
Bipolar disorder is a common condition with no recognized differences in prevalence between gender or ethnic groups. Probands are recruited without regard to sex, religion, race or ethnicity. This approach has, in the past, produced samples that are mostly European-American. Children are excluded because the diagnostic instruments used in this study are not validated in children. Moreover, participation in a family genetic study on bipolar disorder may pose additional risk for children, since they may be unable to understand what it means to be related to people with mental illnesses. Subjects who suffer cognitive impairment and are unable to provide an accurate psychiatric history are excluded since much of the diagnostic information relies on self-report and recall of past events. People too cognitively impaired to give their own consent are excluded.]]>
Cases with bipolar disorder were ascertained opportunistically from clinics, hospitals, and advertisements. Parents are enrolled if available, as well as some unaffected sibling. Participants in AmBiGen all report Amish or Mennonite ancestry. Diagnoses are assigned based on DIGS, medical reports, and family history reports.]]>