The relationship between childhood emotional abuse and chronic pain among people who inject drugs in Vancouver, Canada.

ABSTRACT

BACKGROUND: People who inject drugs (PWID) often contend with chronic pain as a result of illness and trauma, and such pain is known to have significant impacts on mental health, quality of life, and substance use behaviours. Although PWID are also known to have high rates of childhood trauma, little is known about how childhood emotional abuse may be associated with chronic pain in this population. OBJECTIVE: We undertook this study to explore emotional abuse and chronic pain among PWID. PARTICIPANTS AND SETTING: This study comprised a total of 1459 participants in Vancouver, Canada between June 2014 and November 2016. METHODS: We employed multivariable generalized estimating equations with data derived from two prospective cohort studies of community-recruited PWID to examine the relationship between childhood emotional abuse and chronic pain in the past six months. RESULTS: Among eligible participants, 591 (40.5%) reported childhood emotional abuse, and 760 (52.1%) reported chronic pain in the previous six months. In a multivariable analysis, experiencing childhood emotional abuse remained independently associated with chronic pain (adjusted odds ratio 1.25; 95% confidence interval 1.01-1.53) after adjustment for a range of socio-demographic and drug use confounders. CONCLUSIONS: Our findings suggest that childhood emotional abuse may have lasting relationships with chronic pain among PWID, potentially through established physiological and psychological mechanisms. Current chronic pain treatment may benefit from the evaluation of life course vulnerabilities that may be amenable to earlier interventions. Further, increased availability of effective trauma-informed chronic pain treatment is needed among this vulnerable population.