ED utilization that KPNC did not pay for is not captured, although we capture external, paid-for ED utilization through claims. Consequently, ED use may be higher than we report. Low base rates of SUDs other than alcohol, marijuana, and opioid use disorders precluded our ability to examine the effect of these conditions on ED visits.Marijuana is one of the most commonly used drugs worldwide. In the U.S., 47% of adults report lifetime marijuana use and 13% endorse past-year use. It is estimated that 30% of those who use marijuana may have some degree of marijuana use disorder. The acquired preparedness model 4 has been theorized to explain substance use behaviors, wherein individuals who are high on risky personality traits are predisposed to learn certain beliefs and expectations regarding substance use, which in turn influence their substance use behavior. Therefore, the APM proposes a mediational model in which high-risk traits influence specific patterns of psychosocial learning and ultimately increase risk for problematic substance use outcomes. Most of the literature supporting the APM comes from studies on alcohol behavior among college students , although a few studies have begun to apply this model to other substances, including marijuana . Two of the previous studies focused on marijuana found evidence for a mediating role of negative expectancies between personality traits and marijuana outcomes. The direction of the effect differed in these studies. Hayaki and colleagues found that individuals with high impulsivity had more negative expectancies, which in turn, led to reduced frequency of use, drying cannabis while Vangness and colleagues found that individuals with high impulsivity had fewer negative expectancies and used marijuana more frequently.
Furthermore, the former study found a direct mediational role of negative expectancies in the associations between impulsivity and marijuana problems, as well as between impulsivity and marijuana dependence. Two of the three prior studies found a mediating role of positive expectancies in the association between impulsivity and marijuana use among samples of adult marijuana users from the community. Due to the inconsistent findings in the few studies that have evaluated the APM for marijuana outcomes, additional research is needed to parse out the role of positive and negative expectancies. Although the three studies discussed above have tested the APM for marijuana outcomes, all used non-clinical samples. It is important to evaluate these associations in more severe populations as findings from such studies can be particularly helpful in informing prevention and intervention efforts for individuals at-risk. Prior research demonstrates greater impulsivity in individuals with substance use disorders than healthy controls , as well as a link between impulsivity and later cannabis use and abuse . In addition, research shows greater impulsivity among adolescents in treatment for serious substance and conduct problems than community controls. The present study expands on the APM literature by evaluating two marijuana outcomes, i.e. frequency of use and marijuana use disorder symptom count, in an at-risk sample of young adults with a history of both substance use and conduct disorder symptoms and their siblings. The siblings are considered lower risk than the probands, but higher risk than community counterparts. We hypothesized that marijuana expectancies would mediate the relationship between impulsivity and marijuana outcomes among this at risk sample.
However, given the discrepancy in the past literature, we had no a priori hypotheses regarding whether positive and/or negative expectancies would be significant mediators. Probands were originally identified via treatment programs and schools in San Diego County, CA and had to have one or more lifetime substance use disorder symptom and at least one conduct disorder symptom. Siblings of probands also were recruited, but did not need to meet the previously mentioned criteria. Overall, the siblings have been shown to be at higher risk for substance use and antisocial behavior than community samples, but symptom counts were not as high as those of the probands. At the time of original recruitment, probands were between 14 and 19 years old, and their siblings were between 14 and 27 years old. A follow-up assessment, which included self-reported measures of impulsivity and marijuana expectancies, was conducted approximately six years after the original assessment. As the impulsivity measure was not administered at baseline, the present study only used data collected on probands and siblings at the follow-up assessment. Participants older than 30 years of age were excluded from the study to maintain the focus of the study on a sample of young adults. The final study sample consisted of 48% probands, was 54% male, 36% white, 42% Hispanic, and had an average age of 23.5 years .The nested structure of these data presents a potential analytic challenge because related individuals share common family influences with a potential for interdependence among observations. Researchers traditionally measure the degree of interdependence by the intraclass correlations among the observed variables .
However, it has been argued that the “design effect,” which takes into account the average cluster size, is more important in determining the extent of interdependence in the data. In the current sample , 94% of the 180 families had only one proband with no sibling or a proband and one sibling ; there were 10 families with a proband and two siblings. The average cluster size, therefore, was small . This resulted in small design effects for marijuana use and MUD symptoms , suggesting that clustering did not pose a problem for a single-level analysis . As such, the use of multilevel modeling was not warranted, and instead within-family correlation on the outcomes was controlled for using a standard error correction . Indirect effects from sensation seeking to MUD symptoms via positive and negative marijuana expectancies were evaluated using a product-of-coefficients test known as the distribution of the product. The values at the 2.5th and 97.5th percentile reflect the lower and upper limits of the 95% confidence interval; mediation can be said to occur if this confidence interval does not contain zero. Age, gender, and proband status were correlated with marijuana use and therefore included as covariates in the models, which were run separately for marijuana use and MUD symptoms. Descriptive analyses were conducted using SPSS . All indirect analyses were conducted in MPlus version 7.31 using the MLR estimator .This study evaluated the ability of the APM to account for marijuana outcomes in an at-risk sample of young adults. Preliminary analyses showed that sensation seeking was directly associated with higher marijuana use in the past 180 days and more symptoms of MUD. Other impulsivity facets, such as lack of perseverance, negative urgency, and positive urgency, were directly associated with MUD symptoms, but not with marijuana use in the past 180 days. Given that we wanted to evaluate both marijuana outcomes, the following discussion of the APM only refers to sensation seeking as the independent variable. We hypothesized that we would find a significant mediating relationship of marijuana expectancies on the relationship between impulsivity and marijuana outcomes. However, given the discrepancy in the prior APM literature regarding marijuana outcomes as well as the use of different measures of impulsivity , drying weed we had no a priori hypotheses on which facets of impulsivity and which type of marijuana expectancies would be significant in mediational models. Results indicated that only positive marijuana expectancies mediated the associations between sensation seeking and marijuana outcomes in this at-risk sample. Our findings suggest that higher sensation seeking is related to increased positive beliefs about marijuana outcomes, which is related to higher marijuana use and more MUD symptoms. In this way, our findings are consistent with the APM, which theorizes that certain “risky” traits predispose individuals to acquire certain beliefs, such as positive expectancies, which, in turn, lead to risky behaviors and negative consequences. This finding is particularly relevant for the sample used in this study, as individuals with a childhood history of antisocial behaviors and substance use tend to show increased levels of impulsivity. This study adds to the existing literature, which has been inconsistent regarding the role of positive and negative marijuana expectancies as mediators. The current study replicates the findings of two prior studies that demonstrated a mediating role of positive expectancies in the association between impulsivity and marijuana use among samples of adult marijuana users from the community. On the other hand, the current study did not find a mediating role of negative expectancies in the association between sensation seeking and marijuana use, which was previously demonstrated. In the present study, only positive marijuana expectancies mediated the association between sensation seeking and MUD symptoms.
It is possible that this inconsistency relates to the atrisk nature of our sample and that in our sample, 90% of the participants reported lifetime use of marijuana. For example, a study using an at-risk young adult sample found that negative expectancies in adolescence prevented marijuana use in young adulthood; however, 82% of the young adults reported never using marijuana. On the other hand, a research study using a clinical sample found that positive cannabis outcome expectancies, but not negative outcome expectancies, were a direct predictor of marijuana use. This is consistent with other research with individuals endorsing substance misuse, which shows that positive expectancies seem to play a more salient role in substance use behavior than negative expectancies. The literature has shown negative expectancies primarily play a role in preventing tobacco use, as well as influencing positive changes in alcohol treatment. It also is possible that we used a more nuanced measure of impulsivity than used in prior studies. That is, our study used the UPPS-P framework , which identifies five separate, though related, impulsivity facets. A recent meta-analysis of various UPPS-P impulsivity facets and marijuana-related outcomes found that marijuana use was associated with all impulsivity-related facets except lack of perseverance and that negative marijuana consequences were only significantly related to sensation seeking, lack of planning, and positive urgency. This meta-analysis also found small effects for marijuana use and medium effects for marijuana consequences . Because our analyses tested a mediational model that included marijuana expectancies, it is noteworthy that only the facet of sensation seeking, the tendency to seek sensory pleasure and excitement, was a significant impulsivity facet in the mediational model which also included positive expectancies and marijuana outcomes. The current study has several limitations. First, as neither the impulsivity nor the expectancy measures were administered at baseline, we utilized cross-sectional data collected at the follow-up assessment. Impulsivity is a more distal, stable, trait-like construct, whereas expectancies are more proximal and fluid, and therefore, a mediational model is acceptable, but not ideal. Future research would benefit from longitudinal designs, capturing changes in expectancies, marijuana use, and negative consequences. Second, marijuana use was measured using a single item, which is prone to self-report and recall biases. Although using single items to capture specific substance use behaviors is a common practice ,utilizing a method such as the timeline followback may provide a more nuanced and accurate assessment of substance use. Despite these limitations, the findings suggest that positive expectancies are a potentially important risk factor for marijuana use and misuse, particularly for at-risk individuals with elevated rates of sensation seeking. There is extensive empirical support for interventions that challenge expectancies of alcohol use . As such, challenging expectancies about marijuana’s positive effects may be an effective intervention for reducing marijuana related problems among at-risk individuals.Already the most commonly used illicit drug in the United States, marijuana is becoming more widely used and more potent with expanded legalization. Legalization has also popularized “edible” forms of marijuana, including teas and food products. Although often portrayed as a harmless drug with potential therapeutic uses, marijuana has detrimental effects on brain development, psychiatric health , lungs and heart . Public perception of these risks decreases with legalization, and no guidelines exist to help patients gauge the personal safety of use. As emergency providers treat more patients with cannabis use disorders, they must educate patients about these chronic health risks and also manage the acute medical and psychiatric complications of marijuana intoxication. To illustrate the management of acute complex marijuana intoxication and psychosis, we present a case of a woman requiring prolonged emergency department management after ingestion of edible tetrahydrocannabinol , the active ingredient in marijuana.A 34-year-old woman with no significant psychiatric history presented to the emergency department with erratic and disruptive behavior. She broke into a neighbor’s home, requesting to “go to heaven.” She feared people were stealing from her and that “something bad” was going to happen. She reported insomnia, racing thoughts, and euphoria for the past week.