Bipolar disorder has a strong and complex genetic component. perhaps one reason that the genetic component of bipolar disorder is so strong is that

It is passed on from one generation to another

Explanation:

The studies conducted till date on families having hierarchical occurrence of bipolar disorder represents that BP is caused because of linkages in the chromosomal regions. Since this disorder reoccur in the next generation, biologist believe that there are high chances that BP is associated with gene Some specific genes have also been found and suspected to be associated with BP and these are G72/DAOA, TPH2, DISC1,5-HTT, and NRG1.