Washington: Heavy drinkers not only face a higher risk of car accidents and domestic violence, but alcohol also actually rewires the brain, negating recovery from a traumatic experience also, says a US research.
"There`s a whole spectrum to how people react to a traumatic event," said study author Thomas Kash, assistant professor of pharmacology at the University of North Carolina School of Medicine.
"Its the recovery that we`re looking at - the ability to say `this is not dangerous anymore`. Basically, our research shows that chronic exposure to alcohol can cause a deficit with regard to how our cognitive brain centres control our emotional brain centres," said Kash, the journal Nature Neuroscience reports.
"A history of heavy alcohol abuse could impair a critical mechanism for recovering from a trauma, and in doing so put people at greater risk for PTSD (post-traumatic stress disorder) and alcohol abuse," said National Institute on Alcohol Abuse and Alcoholism (NIAAA) scientist Andrew Holmes, who conducted the study with Kash, according to a North Carolina statement.
Over a month, researchers gave one group of mice doses of alcohol equivalent to double the legal driving limit in humans. A second group of mice was given no alcohol. The team then used mild electric shocks to train all the mice to fear the sound of a brief tone.
When the tone was repeatedly played without the accompanying electric shock, the mice with no alcohol exposure gradually stopped fearing it. The mice with chronic alcohol exposure, on the other hand, froze in place each time the tone was played, even long after the electric shocks had stopped.
The pattern is similar to what is seen in patients with PTSD, who have trouble overcoming fear even when they are no longer in a dangerous situation. The PTSD is a debilitating condition that follows a terrifying event. Often, its victims have persistent frightening thoughts and memories of their ordeal and feel emotionally numb.