Comparison of psychiatric co-morbidity in treatment-seeking, opioid dependent patients with versus without chronic pain.

Abstract

AIM\nTo compare psychiatric morbidity in treatment-seeking, opioid-dependent patients with versus without chronic pain.\n\n\nDESIGN\nA retrospective comparative cohort design was used involving record linkage from routinely-collected, nationally-held datasets. Data were managed within a Scottish Government-certified Safe Haven.\n\n\nSETTING AND PARTICIPANTS\nParticipants comprised all patients of an NHS Substance Misuse Service in the East of Scotland (N=521) who were in treatment during the calendar year 2005 and had been in treatment for varying lengths of time. Their mean age at study inception was 35.0 years in the chronic pain group and 32.1 years; 32.2% of the chronic pain group and 26.4% of the no pain group were female.\n\n\nMEASUREMENTS\nThe outcomes were a) psychiatric co-morbidity assessed at study inception using the 28-item General Health Questionnaire and the Clinical Outcomes in Routine Evaluation - Outcome Measure, and b) receipt of at least one prescription for a psychiatric condition over a 5-year period following study inception. The independent variable was chronic pain measured at study inception using the Brief Pain Inventory - Short Form.\n\n\nFINDINGS\n246 (52.7%) reported chronic pain and 221 (47.3%) did not. A higher proportion of patients with chronic pain had at least one psychiatric morbidity (62.4% versus 46.3%, p<0.001). At the study inception a higher proportion of patients with chronic pan were prescribed anxiolytics (49.0% versus 39.1%, p=0.015) and antimanic drugs (9.9% compared with 4.9%, p=0.015).\n\n\nCONCLUSIONS\nPatients of opioid treatment services in Scotland who report chronic pain may have a higher prevalence of psychiatric co-morbidity than those who do not.