Numerous studies have shown that childhood trauma, including child abuse and neglect, lead to brain abnormalities, changes in brain structure and function. Recent studies have used modern technologies such as MRI and fMRI scans to make these showings.
A number of studies have focused on damage to the hippocampus, the area of the brain involved with emotion, memory, and consolidation of information. Research has shown that the hippocampus is affected and damaged by excessive continuing stress caused by continuing trauma such as child abuse or ongoing violence in the home.
A recent study out of Yale University, published in the the journal JAMA Psychiatry on June 11, 2014, focused on the affect of the hippocampal damage of subjects who experienced childhood maltreatment on recalcitrant drug addiction and likelihood of relapse. Performing brain scans on 175 patients undergoing drug treatment and on controls who were not currently drug addicted, the Yale researchers found that individuals who has undergone childhood maltreatment suffered damage to the hippocampal region of the brain. They also made the finding that those who had suffered childhood maltreatment and had damage to their hippocampus were more likely to relapse in their substance abuse disorder.
You can read the results of this study online at the following link: Childhood Maltreatment, Altered Limbic Neurobiology, and Substance Use Relapse Severity via Trauma-Specific Reductions in Limbic Gray Matter Volume