Chronic alcohol exposure can lead to disruptions in the sleep cycle, not just when one actively drinks but even years after one stops drinking.Inpiduals with alcohol use disorder frequently suffer from severely disrupted sleep, said the study co-authored by an Indian-origin professor."Sleep-wake disturbances can last for months, or even years after someone stops drinking. It indicates that chronic alcohol abuse could cause long-term negative effects on sleep," said senior author Subimal Datta, a professor of psychiatry and neurology at Boston University School of Medicine in the US.Sleep disruption can occur when people are actively drinking, when they are going through withdrawal or when they are abstaining.As a result of the prolonged alcohol exposure, the activity of chemicals that excite neurons in the brain increases while simultaneously decreasing the activity of a chemical that inhibits this neuron activity.This results in the over-activity of brain chemicals in the brain and causes a disruption in the normal sleep cycle, the findings noted."Identifying the specific mechanisms that lead to change in brain activity will allow us to develop targeted medications, which could help treat people suffering from sleep issues related to alcohol use disorders," Datta stressed.The review article appeared online in the journal Behavioral Brain Research.