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 people with major depressive disorder and 10,000 people with bipolar disorder to participate in the study. Those who apply must have received a diagnosis from a physician, currently have a prescribed medication and live in the United States. The company is soliciting participants both from its own database of customers who have consented to participate in research, and from other sources such as online forums where people discuss their symptoms.

The study will last for 9 months, and involves both monthly assessments and surveys. 23andMe research manager Anna Faaborg describes it as the "most intensive yet."

23andMe caused a big splash in 2016 when its study of more than 450,000 customers found a number of genetic clues linked to depression. For a long time, it wasn't clear that it had a genetic component, said the company's vice president of business development Emily Drabant Conley.

But 23andMe proved otherwise: "It turned out that we just needed a really big data-set to see them," she said.

23andMe can more easily recruit participants for its studies than researchers at academic institutions as it can email information out to its huge database of consumers, and it offers its surveys via a smartphone. Traditional research often requires participants to travel to research sites.

This new research is intended to build on 23andMe's findings about the genetic links to depression by looking at other variables, including environmental ones.

23andMe's Drabant Conley said the results might ultimately influence how pharmaceutical companies develop drugs to treat these conditions. "It might change the way that symptoms are treated," she said.