Patterns in adolescent cannabis use predict the onset and symptom structure of schizophrenia-spectrum disorder

Countering online marketing and user endorsements with enhanced cannabis warning labels: An online experiment among at-risk youth and young adults

As cannabis legalization expands and online marketing intensifies, this study examines whether online social cues can amplify youth-targeted cannabis advertising and whether cannabis warning labels (CWLs) can counteract these influences. A U.S. online sample of 970 adolescents and 1776 young adults susceptible to cannabis use were recruited from Qualtrics in summer 2022. Each participant was randomly assigned to one of the 3 (CWLs: none vs. textual vs. pictorial) by 3 (comments: none vs. anti-cannabis vs. pro-cannabis) conditions in an online experiment. Participants were exposed to three online marketing posts promoting marijuana edibles (randomly selected from a large pool, N = 1260), each with either no warning label, a textual warning, or a pictorial warning (text and picture), and with either five comments (pro- or anti-cannabis in valence) or none. Results showed that among adolescents, pro-cannabis comments increased product appeal (vs. anti-cannabis comments: b = 0.18, p = .025; vs. no comments: b = 0.21, p = .021), and did so more than young adults. For adolescents, only pictorial warnings reduced product appeal (b = -0.20, p = .028). For young adults, both pictorial (b = -0.18, p = .002) and textual warnings (b = -0.12, p = .029) reduced product appeal. Furthermore, both textual (adolescents: b = -0.20, p = .004; young adults: b = -0.15, p = .005) and pictorial (adolescents: b = -0.30, p < .001; young adults: b = -0.18, p = .001) warnings reduced cannabis use intentions. Findings support requiring enhanced CWLs accompany online marketing ads.

Scoping Review of Cannabis-Reduction Psychosocial Interventions and Reasons for Use among Young Adults with Psychosis

Objective: No evidence-based intervention effectively reduces cannabis use in young adults with psychosis (YAP). To generate hypotheses about why, a scoping review was conducted to synthesize evidence about motivations for cannabis use and reduction/cessation for YAP and the psychosocial interventions trialed to identify possible gaps between motivations and interventive strategies. Methods: A systematic literature search was conducted in December, 2022. Reviews of titles and abstracts (N = 3,216) and full-texts (n = 136) resulted in 46 articles. Results: YAP use cannabis for pleasure, to reduce dysphoria, and for social and recreational reasons; motivations for cessation include insight about cannabis-psychosis interactions, incompatibility with goals and social roles, and support from social networks. Interventions with at least minimal evidence of efficacy include motivational interviewing, cognitive-behavioral strategies, and family skills training. Conclusions: Authors recommend additional research on mechanisms of change and motivational enhancement therapy, behavioral activation, and family-based skills interventions matched to YAP motivations for use/cessation.

Perinatal iron deficiency as an early risk factor for schizophrenia

Growing evidence indicates that a suboptimal intrauterine environment confers risk for schizophrenia. The developmental model of schizophrenia posits that aberrant brain growth during early brain development and adolescence may interact to contribute to this psychiatric disease in adulthood. Although a variety of factors may perturb the environment of the developing fetus and predispose for schizophrenia later, a common mechanism has yet to be elucidated. Micronutrient deficiencies during the perinatal period are known to induce potent effects on brain development by altering neurodevelopmental processes. Iron is an important candidate nutrient to consider because of its role in energy metabolism, monoamine synthesis, synaptogenesis, myelination, and the high prevalence of iron deficiency (ID) in the mother-infant dyad. Understanding the current state of science regarding perinatal ID as an early risk factor for schizophrenia is imperative to inform empirical work investigating the etiology of schizophrenia and develop prevention and intervention programs. In this narrative review, we focus on perinatal ID as a common mechanism underlying the fetal programming of schizophrenia. First, we review the neural aberrations associated with perinatal ID that indicate risk for schizophrenia in adulthood, including disruptions in dopaminergic neurotransmission, hippocampal-dependent learning and memory, and sensorimotor gating. Second, we review the pathophysiology of perinatal ID as a function of maternal ID during pregnancy and use epidemiological and cohort studies to link perinatal ID with risk of schizophrenia. Finally, we review potential confounding phenotypes, including nonanemic causes of perinatal brain ID and future risk of schizophrenia.

High genes: Genetic underpinnings of cannabis use phenotypes

Cannabis is one of the most widely used substances across the globe and its use has a substantial heritable component. However, the heritability of cannabis use varies according to substance use phenotype, suggesting that a unique profile of gene variants may contribute to the different stages of use, such as age of use onset, lifetime use, cannabis use disorder, and withdrawal and craving during abstinence. Herein, we review a subset of genes identified by candidate gene, family-based linkage, and genome-wide association studies related to these cannabis use phenotypes. We also describe their relationships with other substances, and their functions at the neurobiological, cognitive, and behavioral levels to hypothesize the role of these genes in cannabis use risk. Delineating genetic risk factors in the various stages of cannabis use will provide insight into the biological mechanisms related to cannabis use and highlight points of intervention prior to and following the development of dependence, as well as identify targets to aid drug development for treating problematic cannabis use.

Disentangling the lasting effects of adolescent cannabinoid exposure

Cannabis is the most widely used illicit substance among adolescents, and adolescent cannabis use is associated with various neurocognitive deficits that can extend into adulthood. A growing body of evidence supports the hypothesis that adolescence encompasses a vulnerable period of development where exposure to exogenous cannabinoids can alter the normative trajectory of brain maturation. In this review, we present an overview of studies of human and rodent models that examine lasting effects of adolescent exposure. We include evidence from meta-analyses, longitudinal, or cross-sectional studies in humans that consider age of onset as a factor that contributes to the behavioral dysregulation and altered structural or functional development in cannabis users. We also discuss evidence from preclinical rodent models utilizing well-characterized or innovative routes of exposure, investigating the effects of dose and timing to produce behavioral deficits or alterations on a neuronal and behavioral level. Multiple studies from both humans and animals provide contrasting results regarding the magnitude of residual effects. Combined evidence suggests that exposure to psychoactive cannabinoids during adolescence has the potential to produce subtle, but lasting, alterations in neurobiology and behavior.

Adolescent Substance Use and the Brain: Behavioral, Cognitive and Neuroimaging Correlates

Adolescence is an important ontogenetic period that is characterized by behaviors such as enhanced novelty-seeking, impulsivity, and reward preference, which can give rise to an increased risk for substance use. While substance use rates in adolescence are generally on a decline, the current rates combined with emerging trends, such as increases in e-cigarette use, remain a significant public health concern. In this review, we focus on the neurobiological divergences associated with adolescent substance use, derived from a cross-sectional, retrospective, and longitudinal studies, and highlight how the use of these substances during adolescence may relate to behavioral and neuroimaging-based outcomes. Identifying and understanding the associations between adolescent substance use and changes in cognition, mental health, and future substance use risk may assist our understanding of the consequences of drug exposure during this critical window.