Scientists began suspecting mental illnesses may be genetic over 30 years ago after conducting the first twin studies involving schizophrenia. Bipolar disorder also appears to have a genetic component involving gene variations responsible for coding cellular operations that regulate calcium flow to brain cells.
The CACNA1C gene variation found to play a key role in the development of bipolar disorder is also associated with depression and schizophrenia. It further regulates brain activity involved in cognition, emotion, memory and attention — all functions impacted by mental illness.
Researchers have also discovered variations in specific areas of chromosome 3 and chromosome 10 in people with bipolar disorder, schizophrenia and depression. However, it is the variated region in chromosome 3 that presents the strongest correlation to bipolar disorder in genetic studies.
Children and teenagers at risk for bipolar disorder because they carry certain genes may also be more sensitive to stressors than children without the gene. In addition to life event stressors, other things that could trigger bipolar genes in children under 18 years old could involve diet, abnormal sleep/wake cycles and serious viral illnesses.