Schizophrenia can affect how a person perceives reality, thinks, and communicates, sometimes causing hallucinations, delusions, disorganized thinking, reduced motivation, and cognitive difficulties. Bipolar disorder primarily involves episodes of extreme changes in mood and energy, including mania and depression. Some people with bipolar disorder also experience psychosis, which can make the two conditions difficult to distinguish.Now, a study published in Frontiers in Psychiatry has revealed another similarity. In brain scans, people with either condition showed less coordination among widely separated brain regions than people without either diagnosis. The differences were more widespread in schizophrenia.Psychiatrist Li Zhang of Anhui Medical University in China and colleagues compared resting-state functional MRI scans from 89 people with schizophrenia, 57 with bipolar I disorder, and 45 healthy controls. All participants were between 18 and 50 years old.The participants did not perform a task during the scans. Instead, the researchers recorded how activity changed across the brain while each person rested.The team divided the brain into 90 regions and looked for regions whose activity rose and fell at similar times. When two regions show coordinated activity over time, researchers describe them as functionally connected. Functional connectivity does not reveal literal brain 'wiring', such as the physical nerve fibers between regions, nor does it prove that two regions communicate directly.