Many studies have identified variations in the genetic code that seem to be more common in people with psychiatric disorders. This approach goes a step further to show how genes are more or less active in the brains of people with various conditions. The study confirmed that genetic variations contributed to the patterns of activity in the brains, but as the authors wrote, “there is undoubtedly a contribution from environmental effects.” Psychiatric disorders have some overlapping symptoms, making them difficult to diagnose. The molecular signatures in the new study suggested that schizophrenia, bipolar disorder and autism have dysfunctional synapses, the points of...