Page "Bipolar disorder" Paragraph 20

Findings point strongly to heterogeneity, with different genes being implicated in different families.

A review seeking to identify the more consistent findings suggested several genes related to serotonin ( SLC6A4 and TPH2 ), dopamine ( DRD4 and SLC6A3 ), glutamate ( DAOA and DTNBP1 ), and cell growth and / or maintenance pathways ( NRG1, DISC1 and BDNF ), although noting a high risk of false positives in the published literature.

It was also suggested that individual genes are likely to have only a small effect and to be involved in some aspect related to the disorder ( and a broad range of " normal " human behavior ) rather than the disorder per se.