Marijuana use among adolescents is associated with deleterious alterations in mature BDNF

Serum brain-derived neurotrophic factor level and its relation with cannabis use disorder and schizophrenia: A cross-sectional exploratory study in patients at a tertiary care hospital

BACKGROUND

Brain-derived neurotrophic factor (BDNF) has considerable relevance in neural growth and differentiation. It has been evaluated as a biomarker for individuals with various psychiatric disorders such as substance-related disorders and psychotic disorders.

OBJECTIVE

The present study explored differences in the levels of BDNF (in serum) among subjects using cannabis (with and without schizophrenia).

METHODS

This cross-sectional observational study compared the serum BDNF level in male subjects aged 18-45 years. Four groups of 20 subjects each were included: individuals with tobacco use disorder only, patients having schizophrenia, patients with cannabis use disorder, and finally patients with comorbid cannabis use disorder and schizophrenia.

RESULTS

The BDNF levels were found to be significantly different across the four groups. The BDNF levels in subjects with concurrent schizophrenia and cannabis use disorder were higher than each of the other three groups (cannabis use disorder, schizophrenia, and tobacco use disorder only).

CONCLUSION

We find that BDNF may be higher when cannabis use disorder and schizophrenia co-occur, as compared to either of the conditions alone. The findings should be interpreted with caution due to the low sample size and potential confounders.

Effect of cannabis use on blood levels of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF): A systematic review and meta-analysis

BACKGROUND

The impact of cannabis uses on blood levels of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) remains uncertain, with conflicting findings reported in the literature. BDNF and NGF both are essential proteins for neuron's growth, and their dysregulation is seen in various mental disorders. This study aims to evaluate the relationship between cannabis usage and BDNF and NGF levels due to their potential implications for mental health.

METHODS

A comprehensive search of electronic databases was performed using appropriate MeSH terms and keywords. Inclusion criteria comprised human studies investigating the relationship between cannabis use and BDNF and NGF levels.

RESULTS

A total of 11 studies met the inclusion criteria and were included. The pooled analysis revealed a nonsignificant association between cannabis use and dysregulated blood levels of BDNF (random-effects model, standardized mean differences [SMD] = .26, 95% CI -.34 to .76, p = .40). The results of our subgroup analysis based on BDNF source showed a nonsignificant between-group difference. For NGF levels, four studies were included, the pooled analysis revealed a nonsignificant association between cannabis use and dysregulated blood levels of NGF (random-effects model, SMD = -.60, 95% CI -1.43 to -.23, p = .16). In both analyses, high heterogeneity was observed among the included studies which is a notable limitation to current meta-analysis.

CONCLUSION

This systematic review highlights the need for further research to elucidate the relationship between cannabis use and these neurotrophic factors. A better understanding of these associations can contribute to our knowledge of the neurobiological effects of cannabis and inform potential implications for mental health, cognitive function, and neurodegenerative disorders.

Brain-Derived Neurotrophic Factor Levels in Cannabis Use Disorders - A Systematic Review and Meta-Analysis

The prevalence of cannabis use disorders has become a noteworthy global public health issue. Understanding the neurobiological factors associated with cannabis use disorder (CUD) is crucial for creating effective interventions. One such factor, the brain-derived neurotrophic factor (BDNF), has been linked to the onset and persistence of addictive behaviors. This systematic review aims to summarize the existing literature on BDNF levels in individuals with CUD to provide a comprehensive overview of the current evidence. A systematic search was conducted using electronic databases (PubMed, Scopus) for relevant studies. The search approach yielded a total of 785 articles, with 559 located in the PubMed database and 226 in Scopus. Studies reporting BDNF levels in individuals with CUD compared to healthy controls were included in this study. Ultimately, eight articles were included in this systematic review. The primary emphasis of these studies was on individuals who were cannabis users or had a dependency on cannabis. There is considerable variation in the estimated effect size among included studies due to heterogeneity; hence, a random effect model was used for meta-analysis. The findings of our study suggest that the effect size of BDNF levels was 0.25 with 95% CI (-0.55; 1.05) in cannabis users, which was not statistically significant (p-value=0.54). Therefore, it is important to interpret the results with caution, and additional research is warranted to investigate the potential factors contributing to this heterogeneity.

Reversing the Psychiatric Effects of Neurodevelopmental Cannabinoid Exposure: Exploring Pharmacotherapeutic Interventions for Symptom Improvement

Neurodevelopmental exposure to psychoactive compounds in cannabis, specifically THC, is associated with a variety of long-term psychopathological outcomes. This increased risk includes a higher prevalence of schizophrenia, mood and anxiety disorders, and cognitive impairments. Clinical and pre-clinical research continues to identify a wide array of underlying neuropathophysiological sequelae and mechanisms that may underlie THC-related psychiatric risk vulnerability, particularly following adolescent cannabis exposure. A common theme among these studies is the ability of developmental THC exposure to induce long-term adaptations in the mesocorticolimbic system which resemble pathological endophenotypes associated with these disorders. This narrative review will summarize recent clinical and pre-clinical evidence that has elucidated these THC-induced developmental risk factors and examine how specific pharmacotherapeutic interventions may serve to reverse or perhaps prevent these cannabis-related risk outcomes.

Repetitive transcranial magnetic stimulation as a potential treatment approach for cannabis use disorder

The expanding legalization of cannabis across the United States is associated with increases in cannabis use, and accordingly, an increase in the number and severity of individuals with cannabis use disorder (CUD). The lack of FDA-approved pharmacotherapies and modest efficacy of psychotherapeutic interventions means that many of those who seek treatment for CUD relapse within the first few months. Consequently, there is a pressing need for innovative, evidence-based treatment development for CUD. Preliminary evidence suggests that repetitive transcranial magnetic stimulation (rTMS) may be a novel, non-invasive therapeutic neuromodulation tool for the treatment of a variety of substance use disorders (SUDs), including recently receiving FDA clearance (August 2020) for use as a smoking cessation aid in tobacco cigarette smokers. However, the potential of rTMS for CUD has not yet been reviewed. This paper provides a primer on therapeutic neuromodulation techniques for SUDs, with a particular focus on reviewing the current status of rTMS research in people who use cannabis. Lastly, future directions are proposed for rTMS treatment development in CUD, with suggestions for study design parameters and clinical endpoints based on current gold-standard practices for therapeutic neuromodulation research.

Marijuana and β-estradiol interactions on spatial learning and memory in young female rats: Lack of role of the G protein-coupled estrogen receptor (GPR30)

It has been shown that 17β-estradiol (E2) hormone is an essential biological factor for increasing the sensitivity of women to drug abuse. Recent studies have shown a potential overlap between the molecular pathways of cannabinoids and ovarian hormones. The current study evaluated the interference between the marijuana and E2 effect on spatial learning and memory and the role of the G protein-coupled estrogen receptor (GPR30) in young female rats. The animals were separated into two main groups: intact-ovary and ovariectomized (OVX) rats. The latter group received intraperitoneal injections of E2, G-1 (GPR30 agonist), G-15 (GPR30 antagonist), marijuana, and different combinations of these substances for 28 days. Spatial learning and memory were evaluated by the Morris water maze (MWM) test. We also assessed the BDNF (brain-derived neurotrophic factor) concentration and the hippocampal level of GPR30. The results showed a significant reduction of spatial learning and memory in OVX rats compared to intact-ovary rats, which were restored by E2 replacement. Moreover, treatment with G-1 mimicked E2 effects on spatial learning and memory. Marijuana impaired spatial learning and memory in intact-ovary rats, while improved in OVX rats. We also found that treatment with M + E2 induced significant impairment in spatial learning and memory; however, treatment with M + G1 and M + G15 + E2 showed no significant difference. No significant differences in BDNF expression were observed in experimental groups. These results suggest that marijuana and E2 interact in their effect on spatial learning and memory in young female rats, but GPR30 seems to play no role in this interaction.

Klotho, BDNF, NGF, GDNF Levels and Related Factors in Withdrawal Period in Chronic Cannabinoid Users

Klotho and neurotropic factors have recently been shown to be related to some psychiatric disorders and neurocognitive disorders, but there is no study on this issue within substance users. In this study, brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), glial derived neurotrophic factor (GDNF) and klotho serum levels of a patient group consisting of 27 chronic cannabis users according to the DSM-V and 27 healthy volunteers were compared, and their relationships with other the clinical features of other patients were evaluated. Clinical scales, the Buss-Perry Aggression Scale, and the Substance Craving Scale were repeated on the first day of hospitalisation and on the seventh day of withdrawal. BDNF, GDNF, NGF and klotho levels were analysed using the ELISA method. There was no differences between the cannabinoid use disorder group and the control group regarding their klotho and other neurotrophic levels, but initiation age of cannabis use was negatively correlated with these levels. In addition, there was a relationship between verbal aggression scores and BDNF and NGF levels. There was a positive correlation between klotho and neurotrophic factors in all groups (patient group Day 1, patient group Day 7, control group) (p < 0.01). When comparing the difference between the correlations using the cocor (a comprehensive solution for the statistical comparison of correlations), the klotho-GDNF and klotho-NGF correlations for the first day of the patient group and the control group were different. In this study, rather than a difference in klotho levels and neurotropic factors, a significant relationship between these markers and each other and clinical parameters was demonstrated; further studies are needed to understand the exact mechanism.

Demographics, Substance Use Behaviors, and Clinical Characteristics of Adolescents With e-Cigarette, or Vaping, Product Use-Associated Lung Injury (EVALI) in the United States in 2019

IMPORTANCE

To date, limited information is available on the characteristics of adolescents with e-cigarette, or vaping, product use-associated lung injury (EVALI).

OBJECTIVE

To inform public health and clinical practice by describing differences in demographics, substance use behaviors, and clinical characteristics of EVALI among adolescents compared with adults.

DESIGN, SETTING, AND PARTICIPANTS

Surveillance data reported to the Centers for Disease Control and Prevention during the 2019 EVALI outbreak were used to calculate adjusted prevalence ratios (aPRs) with 95% CIs and to test differences between 360 hospitalized or deceased adolescents vs 859 young adults and 936 adults with EVALI (N = 2155).

MAIN OUTCOMES AND MEASURES

Demographics, substance use behaviors, and clinical characteristics.

RESULTS

Included in this cross-sectional study were 360 hospitalized or deceased adolescents (age range, 13-17 years; 67.9% male) vs 859 young adults (age range, 18-24 years; 72.4% male) and 936 adults (age range, 25-49 years; 65.6% male) with EVALI. Adolescents diagnosed as having EVALI reported using any nicotine-containing (62.4%), any tetrahydrocannabinol (THC)-containing (81.7%), and both (50.8%) types of e-cigarette or vaping products. Informal sources for obtaining nicotine-containing and THC-containing e-cigarette or vaping products were more commonly reported by adolescents (50.5% for nicotine and 96.5% for THC) than young adults (19.8% for nicotine [aPR, 2.49; 95% CI, 1.78-3.46] and 86.9% for THC [aPR, 1.11; 95% CI, 1.05-1.18]) or adults (24.3% for nicotine [aPR, 2.06; 95% CI, 1.49-2.84] and 75.1% for THC [aPR, 1.29; 95% CI, 1.19-1.40]). Mental, emotional, or behavioral disorders were commonly reported; a history of attention-deficit/hyperactivity disorder was almost 4 times more likely among adolescents (18.1%) than adults (4.9%) (aPR, 3.74; 95% CI, 1.92-7.26). A history of asthma was more likely to be reported among adolescents (43.6%) than adults (28.3%) (aPR, 1.53; 95% CI, 1.14-2.05). Gastrointestinal and constitutional symptoms were more common in adolescents (90.9% and 97.3%, respectively) than adults (75.3% and 94.5%, respectively) (aPR, 1.20; 95% CI, 1.13-1.28 and aPR, 1.03; 95% CI, 1.00-1.06, respectively). Because of missing data, percentages may not be able to be calculated from data provided.

CONCLUSIONS AND RELEVANCE

Public health and clinical professionals should continue to provide information to adolescents about the association between EVALI and THC-containing e-cigarette or vaping product use, especially those products obtained through informal sources, and that the use of any e-cigarette or vaping product is unsafe. Compared with adults, it appears that adolescents with EVALI more frequently have a history of asthma and mental, emotional, or behavioral disorders, such as attention-deficit/hyperactivity disorder, and report nonspecific problems, including gastrointestinal and constitutional symptoms; therefore, obtaining a confidential substance use history that includes e-cigarette or vaping product use is recommended.