Stem Cells Shed Light on Bipolar Disorder

Researchers have grown embryonic-like stem cells from patients with bipolar disorder and transformed them into brain cells that are already answering questions about the condition.

The cells, which carry the precisely tailored genetic instructions from the patients’ own cells, behave differently than cells taken from people without the disorder, the researchers report.

“Already, we see that cells from people with bipolar disorder are different in how often they express certain genes, how they differentiate into neurons, how they communicate, and how they respond to lithium," Sue O'Shea, a stem cell specialist at the University of Michigan who led the study, said in a statement.

The work, described in the journal Translational Psychiatry, helps fulfill one of the big promises of stem cells research – using a patient’s own cells to study his or her disease.

Mental illness is especially hard to study. Getting into a living person’s brain is almost impossible, and scientists can’t deliberately cause it in people in order to study it.

Creating animals such as mice with what looks like human mental illness is imprecise at best.

The University of Michigan team turned instead to what are called induced pluripotent stem cells, or iPS cells. These are ordinary skin cells taken from a patient and tricked into turning back into the state of a just-conceived embryo.

They are pluripotent, meaning they can become any type of cell there is. In this case, the Michigan team redirected the cells to become neurons – the cells that make up much of the brain. "This gives us a model that we can use to examine how cells behave as they develop into neurons,” O’Shea said.

Bipolar disorder, once called manic-depression, is very common, affecting an estimated 3 percent of the population globally. It runs in families, suggesting a strong genetic cause, and is marked by mood swings from depression to feelings of euphoria and creativity that’s considered the manic phase.

Half of cases develop before a person turns 25, according to the National Institute on Mental Health. There are many different treatments, including lithium, antidepressants and antipsychotics. But treatment is usually hit and miss and doctors would like better ways of predicting which drugs will work best in different patients.

Having a batch of human brain cells in a lab dish would also offer better ways to test new drugs, the researchers say.