A new study suggests that differences in the expression of gene transcripts—readouts copied from DNA that help maintain and build our cells—may hold the key to understanding how mental disorders with shared genetic risk factors result in different patterns of onset, symptoms, course of illness, and treatment responses. Findings from the study, conducted by researchers at the National Institute of Mental Health (NIMH), part of the National Institutes of Health, appear in the journal Neuropsychopharmacology.