Is bipolar genetic?

Heritable, but not..: ...Genetic. This means that among the 1st degree relatives of someone with bipolar, there is a significantly increased proportion (risk) of bipolar. But not 100%--rather, 22% - 50%. Furthermore, the increased risk is not necessarily for bipolar per se, but for any mood disorder. So, the heritability of bipolar is very unlike, say, eye color. And it is very much affected by the environment as well.

Strong evidence: There is strong evidence to suggest heredity as an element of bipolar disorder. What can also aggravate symptoms of bipolar disorder are stressful environments as well as difficult interpersonal relationships.

Genetics of Bipolar: Although results inconsistent, many earlier studies suggest chromosomal aberrations (specifically chromosome 6q & 8q21). Most studies suggested heterogeneity (several genes involved, specifically those for serotonin, Dopamine & glutamate. Also, there is strong correlation with advanced paternal age, suggesting genetic mutations.

Yes: There is a lot of evidence for a genetic predisposition to bipolar disorder. Twin studies show evidence for genetic predisposition. However, genes are nit the only factor - bipolar disorder, like most mental illnesses have complicated, multifactorial etiologies.

Strong findings: There is strong evidence of genetic predisposition in Bipolar disorder from first degree relatives and generational history studies.