The National Institute of Mental Health conducted the first genome-wide association study of bipolar disorder and discovered that not one specific gene appears to be necessary or sufficient for disease. Instead, several genes were shown to contribute to the risk of bipolar disorder.
Genetic research shows us more and more how mental illness is real and not a result of weak character, laziness or other ignorant based notions.
The study can be found at Molecular Psychiatry - which is an awesome resource. Many research articles are free to read and highlight the biological aspects that cause mental illness.
I wonder if I should get Tom Cruise a subscription?
Zandi, P. et. al. (2007) Genome-wide linkagescan of 98 bipolar pedigrees and analysis of clinical covariates. MolecularPsychiatry. Online publication 15 May 2007; doi:0.1038/sj.mp.4002027