The Endogenous Opioid System as a Pathway of Positive Emotions.

Pleasant emotions take a variety of forms and are a key part of the human experience. Although negative emotions have often been a focus of research, positive emotions, e.g., joy, pleasure, and love, have recently gained more attention. Each of these emotions is rich and complex in its own right. However, positive emotions appear to serve key evolutionary functions, which are mediated by complex biological substrates. This chapter summarizes key research and explores the biological underpinnings of positive emotions, with an emphasis on the roles that endogenous opioids play in the experience, expression, and development of positive emotions. The necessity of emphasizing positive emotions in research is also discussed.

Early onset of cannabis use and alcohol intoxication predicts prescription drug misuse in American Indian and non-American Indian adolescents living on or near reservations.

BACKGROUND: Prescription drug misuse (PDM) is a growing issue within the American Indian (AI) population, especially in younger populations. OBJECTIVES: This study estimates relationships between PDM and early initiation (prior to 14 yrs) of cannabis use and alcohol intoxication for a national sample of AI and non-AI adolescents attending schools on or near reservations. METHOD: Participants were 2580 students (50.2% female; 58.1% AI), ages 15-18, attending schools located on or near an AI reservation. Four models of PDM were estimated: 1) demographic variables; 2) demographics plus cannabis use initiation status; 3) demographics plus alcohol intoxication initiation status; and 4) all variables. All analyses were conducted using multilevel modeling. RESULTS: Results indicated that early onset of cannabis use and alcohol intoxication were individually significant predictors of PDM for AI and non-AI adolescents, with odds ratios (OR) of 47.00 for cannabis (p <.01) and 35.73 (p <.01) for intoxication and with no significant differences by race (AI vs. non-AI). Results also indicated a greater likelihood of PDM when a student was an early initiator of both cannabis use and intoxication than when they were one or the other. Finally, there was a significantly greater association between cannabis use and PDM (ORearlycannabis = 24.95, p <.01) than between intoxication and PDM (ORearlyintoxication = 3.98, p <.01) when both predictors were in the model. CONCLUSIONS: These findings suggest that for AI and non-AI youth who have some shared living experience, early initiation of cannabis use and alcohol intoxication are risk factors that are similarly related to PDM and that targeting early initiation for both groups of adolescents is critical in prevention of PDM.

Reefer madness or much ado about nothing? Cannabis legalization outcomes among young adults in the United States.

In 2012, Colorado became one of the first two U.S. States to legalize cannabis for recreational use for adults 21 and older. Given that cannabis use holds potential physical and mental health risks, particularly among adolescent users, concerns have grown regarding changes in use following this change in policy. Studies examining medical cannabis legalization have found inconsistent changes in cannabis use and prevalence of dependence following medical implementation. However, recreational legalization holds potential unique changes, such as increased availability and social acceptance, as well as decreased price and perceived harm of use. There also may be increased interest in moving to Colorado related to the changes in cannabis laws. Based on past literature, two hypotheses were made for this study. First, college student cannabis use would increase after recreational legalization, however just for those 21 years old and older. Second, there would be a positive relation between the influence of cannabis legislation on out-of-State student's decision to attend a Colorado university and their cannabis use. Data from 5241 undergraduate students was available to test study hypotheses using Pearson's Chi-square, negative binomial regressions, and path analysis. Results indicated that cannabis use increased since recreational legalization for all students, but more so for those over 21 years. No differences in past month use frequency were found between pre- and post-legalization. Influence of cannabis laws on non-resident student's decision to attend a Colorado college predicted lifetime and past 30-day use. Additionally, out-of-State students reported higher past 30-day use than in-State students. These findings may help inform other States considering recreational legalization of potential outcomes, as well as potential interventions.