Researchers have identified several sets of genes linked with abnormal brainwave patterns in people with schizophrenia and psychotic bipolar disorder (PBD). The results reported June 23rd in Translational Psychiatry can help experts learn more about the genetic changes that underlie these disorders and determine whether the same sets of genes are involved in each.

The research was led by Balaji Narayanan, Ph.D., of Olin Neuropsychiatry Research Center, Hartford Hospital, and Yale University, and Godfrey D. Pearlson, M.D., also of Olin Neuropsychiatry Research Center and Yale University. Dr. Pearlson is a Foundation Scientific Council member and a 2000 recipient of a NARSAD Distinguished Investigator grant.

Brainwaves—sometimes called oscillations—are different frequencies of electrical activity in neurons that are related to specific functions in the brain. For instance, theta brainwaves represent learning and memory activity, delta brainwaves are linked to the body’s metabolism, and alpha brainwaves reflect the brain’s “idling” mode. Scientists measure brainwaves with an electroencephalogram or EEG, a technology that records electrical activity using sensors on the scalp.

Earlier studies have shown that people with schizophrenia and PBD have abnormalities in some of these brainwaves, and that these are also found in some of their relatives. To learn more about what causes these abnormalities, Dr. Pearlson and his colleagues compared EEG data and genetic material taken from blood samples of 105 people with schizophrenia, 145 people with PBD, and 56 healthy people. Participants were drawn from the multi-site BSNIP (Bipolar-Schizophrenia Network on Intermediate Phenotypes) study. The team analyzed these data to find out if certain groups of genes were linked to abnormal brainwave patterns.

The researchers uncovered abnormal theta and delta brainwaves in the schizophrenia and PBD patients, although the theta pattern was different in the two disorders. These theta and delta abnormalities were linked with sets of genes that help build new connections between brain cells and control communication pathways between these cells.

The study gives researchers some new leads to follow in understanding the underlying genetics of these disorders. But Dr. Pearlson and colleagues caution that other factors might influence the connection between genes and brainwave patterns, including how severe a patient’s condition might be, and whether he or she is taking antipsychotic medication.

Other team members include Carol A. Tamminga, M.D., a Scientific Council member who received the Distinguished Investigator grant in 1998 and 2010; 1997 Independent Investigator recipients John A. Sweeney, Ph.D. and Matcheri S. Keshavan, M.D.; Brett A. Clementz, Ph.D., a 2000 NARSAD Independent Investigator grant recipient; and Vince D. Calhoun, Ph.D., a 2004 NARSAD Young Investigator recipient.

Read the research paper.