The repercussions of bipolar disorder can devastate an individual’s life with social and career disruptions and suicidal thoughts. The person with bipolar disorder can phase between episodes of paralyzing depression and uncontrollable mania that make it difficult to function in daily life. In order to evaluate a patient for bipolar disorder, a doctor will ask questions about the patient's family’s mental health history to assess whether there is a hereditary connection.
Multiple Gene Involvement
In a study called “Molecular Genetics of Bipolar Disorder,” which was published in a supplement to the "British Journal of Psychiatry" in June 2001, Nick Craddock, Professor of Molecular Psychiatry, states that recent studies have identified regions in the genetic code that predispose an individual to bipolar disorder. Craddock attests that, though no gene has yet been identified, the studies in progress will identify multiple bipolar susceptibility genes, and the knowledge gleaned will greatly impact medical understanding of the causes of the disorder.
Correlation with Schizophrenia Genes
Evidence that was reported by the International Schizophrenia Consortium, and published in the online journal "Nature," has linked bipolar disorder with the same genetic variants that increase a person’s risk of schizophrenia. It has not been determined exactly how these genetic variants manifest as bipolar disorder, and genetic variants alone do not guarantee an eventual bipolar diagnosis.
The director of the National Institutes for Mental Health, Dr. Thomas Insel, has stated that the underlying genetic similarities of schizophrenia and bipolar disorder may indicate a common origin of these disorders that occurs early on in the vulnerable developing brain.
Correlation with Depression Genes
The National Institute of Mental Health reports that gene variants that are common in patients with depression have also been found in those with bipolar disorder. A gene whose coding regulates a cell’s ability to turn genes on and off was determined to be overemphasized in the brains of those with bipolar disorder. The presence of such gene variations may increase a person’s risk for developing bipolar disorder.
Dr. Francis McMahon of the NIMH’s Mood and Anxiety Disorders Program, states that the genes that predispose an individual to bipolar disorder are most likely numerous, with each displaying small effects, rather than having larger effects that would make them easier to identify. McMahon hopes that further research will help identify the causes of bipolar disorder, and lead to more effective forms of treatment.
