At-home DNA-testing company 23andMe is recruiting 25,000 people for a study to determine how genes influence brain functions in people diagnosed with depression and bipolar disorders. The Google-backed company's latest project is a collaboration with the Milken Institute, a medical research nonprofit, and Lundbeck, a drug developer, to study the genetics -- and also symptoms, behavior and other environmental factors --- associated with bipolar and major depressive disorders. In interviews with CNBC, the company describes its goal as finding out how genes influence brain processes, like attention and visual perception, for those with these conditions. 23andMe is currently recruiting 15,000...