4. Understanding the mechanisms that link childhood stress with risk of addiction
Experiences of childhood trauma are disproportionately higher in those with substance use disorders. As a prolonged and early stressor, childhood trauma may affect the reinforcing and rewarding properties of drugs via neurodevelopmental changes. This presentation will focus on multiple international studies that aim to better understand the mechanisms that underlie this link.
Study 1 was a placebo-controlled morphine administration study that assessed the impact of severe childhood trauma on subjective and behavioural measures of opioid reward (University of Exeter). Study 2 is a conceptual replication of Study 1 among people who receive opioid pain medication prior to undergoing surgery (University of Oslo). Study 3 is a secondary data analysis that examines if childhood trauma is linked to altered subjective reward to cannabis in young people who regularly use the drug (University of Queensland).
Study 1 reports greater subjective liking, feeling high, euphoria, and wanting of morphine among people with childhood trauma, paired with reduced reports of aversive effects such as dislike, nausea, and dizziness. Study 2 is ongoing and expected to replicate the Study 1 findings. Study 3 conversely found childhood trauma was linked to more aversive subjective effects of cannabis.
These findings indicate childhood stress such as trauma is linked to altered subjective drug effects, which may differ by the stage of use and the drug. Addressing childhood trauma early through novel preventions may help to attenuate the impacts of trauma prior to substance use, and trauma-informed approaches should be adopted through schools and substance use treatment services.
Disclosure of interest statement: Study 1 was funded by the University of Exeter. Study 2 was supported by European Research Council under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 802885). Study 3 was funded by a grant to Leanne Hides from the Australian Government Department of Health as part of a wider RCT (ACTRN12618001107213). No pharmaceutical grants were received in the development of these studies.