Additionally, we found that activation in the occipital cortex to negative emotional stimuli mediated the relationship between marijuana use and later resiliency. Specifically, activation in the cortical region surrounding the calcarine fissure, including portions ofthe right cuneus and lingual gyrus, was lower in heavy marijuana users than controls. This activation was further associated with decreased resiliency at follow-up, when controlling for resiliency at the time of scan. Although the cuneus and lingual gyrus are classically considered as visual processing and integration regions, there is a large literature associating both regions with aspects of emotion functioning, including the processing of emotional faces,high-arousal emotional words,and emotional film clips,as well as the evaluation of one’s own emotional state.Cuneus activation has also been associated with the ability to attribute mental states to others, termed “theory of mind”. A recent study reported that adult marijuana users had differences in brain activation compared with controls during a ToM task, including lower activation in the right cuneus.Therefore, an impact of heavy marijuana use during adolescence on the functioning of occipital regions involved in the evaluation of emotional stimuli with respect to oneself and to others may impair self-regulation of emotional processes.In addition to the regions found to mediate later outcome, heavy marijuana users had less activation than controls in the insula to negative words. These findings are consistent with previous work showing adolescent marijuana users had reduced cerebral blood flow in the insula compared with controls.Furthermore, studies of adult cannabis grow racks users found less activation in the insula to loss outcomes during a monetary incentive task and to errors in an inhibitory control task compared with controls.
The insula is critical to the integration of emotional and homeostatic information, and may be involved in translating interoceptive signals into conscious feelings.For example, the magnitude of insula activation while participants evaluated their own emotional and bodily states was found to be associated with social anxiety and neuroticism.Insula activation has also been associated with self-report measures of anxiety and anticipation of aversive exposure in anxiety-prone individuals. Here we found less insula activity to negative words in heavy marijuana users compared with controls, which was further associated with more negative emotionality at the time of scan. Together, this evidence suggests that heavy marijuana use may lead to impairment in the integration of emotional experience.Along with the insula, the amygdala is part of a network involved in translating interoceptive responses to emotional stimuli into emotional experience.Blunted amygdala response has been observed in individuals with difficulties experiencing and processing emotions.Acutely, cannabidiol, a psychoactive component of cannabis, has been shown to decrease amygdala activation to anxiety-inducing emotional stimuli; this effect was further associated with a reduction in electrodermal activity,supporting links among marijuana, amygdala functioning, and interoceptive response to emotion. Furthermore, prior evidence indicates that the impact of marijuana use on amygdala-mediated emotional responding is not restricted to negative stimuli. Gruber et al. reported less amygdala activation in adult heavy marijuana smokers compared with controls to both happy and angry faces presented below the level of conscious processing. Here we found less amygdala activation to both positive and negative words in heavy marijuana users compared with controls, which further correlated with negative emotionality. Therefore, marijuana may have an impact on amygdala functioning that impairs general emotional arousal and integration. The finding of an association between negative emotionality and reduced activation of the insula and amygdala is opposite to effects described in the depression and anxiety literature, which reports enhanced activation to negative stimuli.
However, a longitudinal study of individuals with comorbid major depression and marijuana dependence found that greater marijuana use was associated with reduced amygdala activation to emotional stimuli.This suggests that the mechanism through which marijuana impacts negative emotionality differs from the mechanism underlying depression and anxiety. For example, the associations between insula and amygdala functioning and negative emotionality in the current study may be more pertinent to differences in the experience and processing of emotions rather than depression and anxiety. Finally, heavy marijuana users showed reduced activity in the right inferior parietal lobule and greater activation in the right dlPFC during the viewing of positive words. The inferior parietal cortex is part of an attentional system involved in the automatic allocation of attention to task-relevant information,whereas the dlPFC is involved in more effortful attentional control.Thus, the current results suggest a decrease in automatic attention to positive words in heavy users with a corresponding increase in effortful attentional control necessary to attend to the task. This is consistent with prior work demonstrating heightened activation of right-hemisphere prefrontal attentional control circuitry in adolescent marijuana users,which may reflect the need for increased effort in attending to task-related stimuli.This study extends our prior work by providing evidence of reliability and generalizability of a surveillance tool for assessing the marketing practices and socio-contextual characteristics of recreational marijuana retailers. While this study is limited by its focus on a convenience sample of 25 retailers in Seattle chosen from Weed maps, this data builds on prior tool utilization among 20 Denver retailers. This study also helped to identify distinct variables relevant within differing policy contexts.In the current and previous studies,high compliance with age requirement/verification practices, as well as use of security measures, was documented. In terms of promotion, novel products were frequently advertised, likely in an attempt to familiarize customers with newer products.Unlike the Colorado study,however, bud was also frequently advertised among Seattle retailers. Loyalty club memberships and daily/weekly deals were prevalent, similar to the Denver study.
However, using social media was not as common in this sample of Seattle retailers compared to the sample of Denver retailers,which may reflect more conservative policies regarding online promotion and sales in Washington relative to Colorado.Similar to our prior work,this study also documented little product and price variability among the shops. This lack of variability in product offerings and price suggests that other shop characteristics might be used to differentiate retailers from one another. Indeed, unlike the tobacco and alcohol industry, building strong brand affiliation with shops rather than products may be strategic in the marijuana industry, potentially given limited variability in product offerings and price across marijuana retailers.This study highlighted that assessments of the marijuana retail environment should be informed by policies and regulations given activities that may be differentially prohibited or restricted in differing jurisdictions. For example, while marijuana retailers are allowed to sell clones and seeds in Colorado, retail sale of clones and seeds is prohibited in Washington. Similarly, Washington retailers are prohibited from selling branded apparel or other merchandise in the retail store.However, the Colorado market is not restricted in this way. This is particularly relevant given that this study noted violations of these regulations, specifically in relation to the sale of branded apparel in Seattle. Furthermore, this study documented retailers being proximal to schools, parks, and playgrounds, despite regulations limiting them to further than 1000 ft ; however, our assessment tool lacked the specificity to capture if retailers were indeed within 1000 ft. Attempts to circumvent policies are also noteworthy. This study noted that some Seattle retailers had separate storefronts adjacent to the marijuana shop where they could sell branded apparel and justify larger exterior signage. Our previous study in Denver also noted other attempts to circumvent policies; for example, publicizing “private” parties where marijuana use would be allowed despite prohibition of marijuana in public places.Surveillance of such activities is critical to informing regulatory and enforcement efforts. The MRST demonstrated perfect inter-rater reliability in two-thirds of items and ≥0.73 congruence in the remaining items. Incongruence occurred in assessments of the external environment, marketing and promotion, and price.
Greater rigor in training regarding the use of the MRST, including standardized protocols that include examples and practice assessments,cannabis grow system is needed. Additionally, in assessing products, complexities in mode of consumption, tetrahydrocannabinol versus cannabidiol, and strain make thoroughly assessing each product category cumbersome and complicated. Moreover, assessing lowest price across marijuana product categories is complex given the diversity of product offerings in any single product category and the ranges in volume, potency, strain, etc. Thus, this approach will need to be further refined over time and adapted as differing policy contexts may prohibit certain types of products or regulate how they are packaged.Finally, studies involving larger sample sizes could examine differences between recreational only retailers versus those with a medicinal endorsement.A 2015 conference on medical use of marijuana indicated that 23 US states have legalised medical marijuana with some also legalising marijuana for recreational use.Although there is moderate evidence for efficacy of cannabinoids for chronic pain and spasticity, and some evidence for Multiple Sclerosis and treatment-resistant epilepsy, there is not good evidence for its use to treat nausea and vomiting associated with chemotherapy,perhaps the best known indication for medical marijuana. Some pregnant women report using marijuana to alleviate nausea and vomiting in pregnancy with success but evidence for its efficacy is mostly anecdotal. However, reports of adverse events for non-pregnant populations using medical marijuana raise concerns for pregnant marijuana users. According to the National Drug Strategy Household Survey in Australia, 7.6% of females aged ≥14 years used marijuana during 2010,with 34.8% of the female population having used marijuana at least once in their lifetime. A similar trend has also been observed in New Zealand and Europe, with 47.2% of women aged ≥16 years in NZ, 24.6% in the United Kingdom and 17.5% in Ireland having used marijuana at least once. Apart from reported negative impacts on fetal growth and brain development, marijuana has been associated with adverse pregnancy outcomes, including preterm birth,small for gestational age,placental abruption and antepartum haemorrhage. Specifically, studies have shown that using marijuana during pregnancy is associated with low birthweight and increases the risk of PTB and SGA, with an odds ratio of at least 1.5 when adjusted for age, BMI and smoking.
The association between marijuana use and pregnancy outcomes is often confounded by other known risk factors including cigarette smoking, body mass index,and socioeconomic index. Women who use marijuana also tend to smoke cigarettes and are more likely to use other drugs and alcohol, for whom national statistics have shown that amongst Australian women aged ≥14years who used marijuana in 2010, 82.7% also consumed alcohol, and 68.5% were cigarette smokers, with similar patterns of prevalence in New Zealand. There have been inconsistent results reported from American prospective cohort studies, in which associations of marijuana use with adverse pregnancy outcomes were either found or not found. Hence, this study aimed to examine the association of maternal marijuana use in a multi-centre cohort with major pregnancy complications, amongst both cigarette smokers and non-smokers, controlling for well-known risk factors including age, SEI and BMI, as well as its effects on length of gestation.Data from this analysis were obtained from the SCreening fOr Pregnancy Endpoints study, which aimed to build a clinical database and pregnancy biobank to screen candidate markers of pregnancy complications. The SCOPE study recruited nulliparous women with singleton pregnancies between November 2004 and February 2011 from one centre in each of Australia, New Zealand, and Ireland, and three centres in the United Kingdom. Ethical approval was obtained from local ethics committees and all women provided written informed consent. Women were invited to participate prior to 15 weeks’ gestation when attending hospital antenatal clinics, obstetricians, general practitioners or community midwives, and were interviewed and examined by a research midwife at 15 ± 1 and 20 ± 1 weeks of gestation. The exclusion criteria included women who were considered to be at high risk of PE, SGA or PTB due to underlying medical conditions,previous cervical knife cone biopsy, three terminations or three miscarriages or if their pregnancy was complicated by a known major fetal anomaly or abnormal karyotype, or if they received interventions that may modify pregnancy outcome.Details of maternal age, BMI and socioeconomic index1,medical and family history, along with dietary and lifestyle questionnaires with self-reported marijuana and cigarette smoking were recorded at 15 weeks’ and 20 weeks’ gestation and entered into an internet-accessed, password-protected centralised database with a complete audit trail.