Different neurological conditions like autism, schizophrenia and bipolar disorder appear to have more in common than scientists thought they did. A new study finds that they have important similarities at a molecular level.

And understanding the molecular basis of those disorders could help in developing better treatments.

These conditions are diagnosed by how a patient behaves. There are no clear signs on a brain “that you can see with your eyes or most microscopic techniques,” says Dan Geschwind, a professor of neurogenetics at the University of California, Los Angeles. His team’s findings were published in Science this week.

The conditions are different from brain diseases like Alzheimer’s or Parkinson’s, which physically change the brain. In those cases, a doctor can look at a brain and say what the patient suffered from.

But recent advances in genetics allowed the scientists to pinpoint the patterns of gene expression in the brain that are linked to these disorders.

In a large-scale study, they measured RNA in 700 tissue samples from the brains of people with autism, schizophrenia, bipolar disorder, major depression and alcoholism, and compared them with tissue of people without these disorders. RNA can show which genes are turned on and off in the tissue. To read more from MERRIT KENNEDY, click here.