Studies have shown that stress and trauma early in life can lead to an increased risk for drug addiction later in life. In rat models developed to mimic and study this effect, some rats received normal maternal care, while others received enriched maternal care - extra grooming and attention from their mothers. Those with enriched maternal care have been shown to be less likely to return to a room in which the rats received a dose of morphine. But does that accurately represent drug use? They've also been shown to have neurological changes in the brain - but these changes have been correlational. A new study published in the journal Neuropsychopharmacology was set up to tease out a number of aspects of this research.

Article: Opioid Self-Administration is Attenuated by Early-Life Experience and Gene Therapy for Anti-Inflammatory IL-10 in the Nucleus Accumbens of Male Rats

https://www.nature.com/articles/npp201782