How alcohol consumption increases during stress

New Delhi: Increased stress can cause changes in brain's reward centre, which may then lead to a rise in alcohol consumption, a study, with implications to post-traumatic stress disorder (PTSD), has found. In a study, researchers used a rat model to explore the relationship between stress signalling and addictive substance use. Rodents that had been exposed to stress had a weakened alcohol-induced dopamine response and voluntarily drank more alcohol compared to the control group. John Dani, from the University of Pennsylvania, US says, "These effects happen at the minute level of potassium, chloride, and other ions moving across the neuron outer membrane via channels and transporters." "In addition, by chemically blocking stress hormone receptors on neurons, we prevented stress from causing increased drinking behavior. The research has implications for people with PTSD who have an increased risk for over-use of alcohol and drugs." Dani added. The findings may help develop treatment methods for individuals with post-traumatic stress disorder (PTSD), a mental disease characterized by impulsive behavior and often heavy substance abuse. For the study, rats were exposed to an acute stress for one hour, and then 15 hours later, researchers measured the amount of sugar water laced with ethanol that the mice drank. The stressed rats drank significantly more than the control group, and the increase was maintained for several weeks. "The stress response evolved to protect us, but addictive drugs use those mechanisms and trick our brains to keep us coming back for more," Dani further added. Neurons in the experimental group were found to become more excitable over time, driving the rats to consume more ethanol-laced water. After the scientists introduced a chemical called CLP290, stress-altered circuitry returned to normal, the researchers noted in the paper published in the journal Neuron.