The trauma that a majority of drug addicts suffer in early life has now been shown to increase their vulnerability to drug addiction, Yale researchers report in a new study.
"Using well-established animal models, we’ve found strong evidence that early life stress enhances vulnerability to drug addiction," said Therese A. Kosten, assistant professor of psychiatry at Yale School of Medicine. "This study demonstrates the need to target drug abuse prevention strategies to children with early life traumas."
Rat pups that were separated from their mothers for one hour per day during the first week of life learned to self-administer cocaine more readily when they were adults compared to rats that had not had this early life stress. This effect was not due to differences in learning or general activity levels.
"Previous studies show that most drug addicts have had early life trauma," said Kosten, principal investigator on the study. "Given that 1.8 million Americans are currently using cocaine, this information will be valuable in directing future research toward potential interventions for children with early stress experiences in order to reduce the risk of developing drug addiction in adults."
Published in a recent issue of the journal Brain Research, Kosten and her team tested 14 adult rats, eight of which had experienced the stress of isolation from their mother, siblings and nest three months earlier. Compared to six rats that had not experienced this stress, isolated rats learned to press a lever to receive a cocaine infusion in two-thirds the number of days, and at half the dose needed for the non-isolated rats. Kosten said the groups did not differ in the number of days to learn to press a lever to receive food pellets, demonstrating that the isolation effect was specific to cocaine.
Kosten’s research team included Mindy J.D. Miserendino of Sacred Heart University and Priscilla Kehoe of Trinity College. The National Institute on Drug Abuse funded the study.
Journal
Brain Research