A dramatic increase in the use and dependence of prescription opioids has occurred within the last 10 years. The consequences of long-term prescription opioid use and dependence on the brain are largely unknown, and any speculation is inferred from heroin and methadone studies. Thus, no data have directly demonstrated the effects of prescription opioid use on brain structure and function in humans. To pursue this issue, we used structural magnetic resonance imaging, diffusion tensor imaging and resting-state functional magnetic resonance imaging in a highly enriched group of prescription opioid-dependent patients [(n = 10); from a larger study on prescription opioid dependent patients (n = 133)] and matched healthy individuals (n = 10) to characterize possible brain alterations that may be caused by long-term prescription opioid use. Criteria for patient selection included: (i) no dependence on alcohol or other drugs; (ii) no comorbid psychiatric or neurological disease; and (iii) no medical conditions, including pain. In comparison to control subjects, individuals with opioid dependence displayed bilateral volumetric loss in the amygdala. Prescription opioid-dependent subjects had significantly decreased anisotropy in axonal pathways specific to the amygdala (i.e. stria terminalis, ventral amygdalofugal pathway and uncinate fasciculus) as well as the internal and external capsules. In the patient group, significant decreases in functional connectivity were observed for seed regions that included the anterior insula, nucleus accumbens and amygdala subdivisions. Correlation analyses revealed that longer duration of prescription opioid exposure was associated with greater changes in functional connectivity. Finally, changes in amygdala functional connectivity were observed to have a significant dependence on amygdala volume and white matter anisotropy of efferent and afferent pathways of the amygdala. These findings suggest that prescription opioid dependence is associated with structural and functional changes in brain regions implicated in the regulation of affect and impulse control, as well as in reward and motivational functions. These results may have important clinical implications for uncovering the effects of long-term prescription opioid use on brain structure and function.
The longitudinal course of cocaine dependence is characterized by alternating periods of abstinence and relapse. Although gender has emerged as an important predictor of relapse, previous studies have examined mean differences in use by gender. Focusing strictly on differences in averages between men and women does not address potential gender differences in transitions between use and abstinence. Transition rates for men and women were compared using data from the National Institute on Drug Abuse Collaborative Cocaine Treatment Study. Abstinence and nonabstinence for each of the 6 months of active treatment was determined by using a composite measure of use that incorporated information from weekly and monthly self-reports and urine toxicology screenings. Random effects were introduced to describe intersubject heterogeneity in transition rates. In this sample of 454 patients, rates of transition between abstinence and use were significantly different between men and women, with men showing twice the rate of transition between states despite similar average levels of use. These data may have important implications for both treatment planning and the types of outcomes considered in clinical practice and research.
The severity of cocaine dependence of 39 hospitalized patients was assessed by administering the Structured Clinical Interview for DSM-III-R. No significant relationship was found between severity of cocaine dependence and cocaine use at 3-month follow-up. These findings suggest that severity of cocaine dependence may be a poor predictor of relapse to cocaine use.
As overdose rates rise among non-White Americans, understanding barriers to substance use disorder (SUD) treatment access by race and ethnicity is important. This study explores self-reported barriers to SUD treatment by race and ethnicity in emergency department (ED) populations.
