Interactions between cannabis and schizophrenia in humans and rodents

Perturbation of 3D nuclear architecture, epigenomic aging and dysregulation, and cannabinoid synaptopathy reconfigures conceptualization of cannabinoid pathophysiology: part 2-Metabolome, immunome, synaptome

The second part of this paper builds upon and expands the epigenomic-aging perspective presented in Part 1 to describe the metabolomic and immunomic bases of the epigenomic-aging changes and then considers in some detail the application of these insights to neurotoxicity, neuronal epigenotoxicity, and synaptopathy. Cannabinoids are well-known to have bidirectional immunomodulatory activities on numerous parts of the immune system. Immune perturbations are well-known to impact the aging process, the epigenome, and intermediate metabolism. Cannabinoids also impact metabolism via many pathways. Metabolism directly impacts immune, genetic, and epigenetic processes. Synaptic activity, synaptic pruning, and, thus, the sculpting of neural circuits are based upon metabolic, immune, and epigenomic networks at the synapse, around the synapse, and in the cell body. Many neuropsychiatric disorders including depression, anxiety, schizophrenia, bipolar affective disorder, and autistic spectrum disorder have been linked with cannabis. Therefore, it is important to consider these features and their complex interrelationships in reaching a comprehensive understanding of cannabinoid dependence. Together these findings indicate that cannabinoid perturbations of the immunome and metabolome are important to consider alongside the well-recognized genomic and epigenomic perturbations and it is important to understand their interdependence and interconnectedness in reaching a comprehensive appreciation of the true nature of cannabinoid pathophysiology. For these reasons, a comprehensive appreciation of cannabinoid pathophysiology necessitates a coordinated multiomics investigation of cannabinoid genome-epigenome-transcriptome-metabolome-immunome, chromatin conformation, and 3D nuclear architecture which therefore form the proper mechanistic underpinning for major new and concerning epidemiological findings relating to cannabis exposure.

Epigenomic and Other Evidence for Cannabis-Induced Aging Contextualized in a Synthetic Epidemiologic Overview of Cannabinoid-Related Teratogenesis and Cannabinoid-Related Carcinogenesis

BACKGROUND

Twelve separate streams of empirical data make a strong case for cannabis-induced accelerated aging including hormonal, mitochondriopathic, cardiovascular, hepatotoxic, immunological, genotoxic, epigenotoxic, disruption of chromosomal physiology, congenital anomalies, cancers including inheritable tumorigenesis, telomerase inhibition and elevated mortality.

METHODS

Results from a recently published longitudinal epigenomic screen were analyzed with regard to the results of recent large epidemiological studies of the causal impacts of cannabis. We also integrate theoretical syntheses with prior studies into these combined epigenomic and epidemiological results.

RESULTS

Cannabis dependence not only recapitulates many of the key features of aging, but is characterized by both age-defining and age-generating illnesses including immunomodulation, hepatic inflammation, many psychiatric syndromes with a neuroinflammatory basis, genotoxicity and epigenotoxicity. DNA breaks, chromosomal breakage-fusion-bridge morphologies and likely cycles, and altered intergenerational DNA methylation and disruption of both the histone and tubulin codes in the context of increased clinical congenital anomalies, cancers and heritable tumors imply widespread disruption of the genome and epigenome. Modern epigenomic clocks indicate that, in cannabis-dependent patients, cannabis advances cellular DNA methylation age by 25-30% at age 30 years. Data have implications not only for somatic but also stem cell and germ line tissues including post-fertilization zygotes. This effect is likely increases with the square of chronological age.

CONCLUSION

Recent epigenomic studies of cannabis exposure provide many explanations for the broad spectrum of cannabis-related teratogenicity and carcinogenicity and appear to account for many epidemiologically observed findings. Further research is indicated on the role of cannabinoids in the aging process both developmentally and longitudinally, from stem cell to germ cell to blastocystoids to embryoid bodies and beyond.

Childhood traumatic events and the dopaminergic theory of psychosis: A mini-review of studies investigating gene – environment interactions

There is great body of evidence showing a relationship between childhood adversity and psychosis onset. Genetic factors moderate the association between childhood adversity and psychosis risk potentially by influencing biological and/or psychological reaction following exposure to adversity. In this review, we discuss studies identifying the specific genetic variants known to affect dopamine levels involved in this interaction. Our review shows that the catechol-O-methyltransferase (COMT), dopamine D2 receptor (DRD2), AKT1 gene play a key role in mediating the relationship between childhood adversity and development of psychosis. We have also found conflicting findings on the impact of dopamine genes on the relationship between childhood adversity and development of psychosis, suggesting that other genetic and environmental factors should be taken into account. We here discuss the implications of our findings and future directions.

The P2X7 Receptor: Central Hub of Brain Diseases

The P2X7 receptor is a cation channel activated by high concentrations of adenosine triphosphate (ATP). Upon long-term activation, it complexes with membrane proteins forming a wide pore that leads to cell death and increased release of ATP into the extracellular milieu. The P2X7 receptor is widely expressed in the CNS, such as frontal cortex, hippocampus, amygdala and striatum, regions involved in neurodegenerative diseases and psychiatric disorders. Despite P2X7 receptor functions in glial cells have been extensively studied, the existence and roles of this receptor in neurons are still controversially discussed. Regardless, P2X7 receptors mediate several processes observed in neuropsychiatric disorders and brain tumors, such as activation of neuroinflammatory response, stimulation of glutamate release and neuroplasticity impairment. Moreover, P2X7 receptor gene polymorphisms have been associated to depression, and isoforms of P2X7 receptors are implicated in neuropsychiatric diseases. In view of that, the P2X7 receptor has been proposed to be a potential target for therapeutic intervention in brain diseases. This review discusses the molecular mechanisms underlying P2X7 receptor-mediated signaling in neurodegenerative diseases, psychiatric disorders, and brain tumors. In addition, it highlights the recent advances in the development of P2X7 receptor antagonists that are able of penetrating the central nervous system.

Cannabis acute use impacts symptoms and functionality in a cohort of antipsychotic naïve First Episode of Psychosis individuals

Introduction

Cannabis use increases the risk of developing psychosis, and subjects with psychosis are more likely to use cannabis. However, studies on the influence of cannabis on psychotic dimensions, response to treatment, and functional outcomes showed conflicting results. Such heterogeneity may be due the inclusion of patients who were already under treatment, and lack of specificity in evaluations. We investigated whether cannabis use yields distinct symptom profiles and functionality in a cohort of antipsychotic-naïve patients at first episode of psychosis (FEP).

Methods

This research is part of a prospective cohort study performed in Sao Paulo, Brazil. The baseline assessment was completed by 175 individuals, and 99 of them were reassessed in a ten-week follow up. We investigated the relationship between cannabis exposure variables (acute use, lifetime use and age at first use) and outcomes: symptom dimensions and functioning.

Results

Individuals who reported acute use of cannabis had higher excitement symptoms at baseline, higher excitement and positive response rates, but no significant differences at follow-up. Additionally, more days of cannabis use in the last month predicted worse functionality and clinical impression at baseline but not at follow-up.

Discussion

The acute use of cannabis influenced the clinical presentation at our FEP baseline assessment, but did not to influence symptoms or functional outcomes at 10-week follow-up. Additionally, acute cannabis users had a better response for excitement and positive symptoms. Higher excitement symptoms at presentation of FEP should raise concerns of possible acute use of cannabis. Longer follow-up times may elucidate whether the effects on functionality would be more evident later in disease development.

Holistic Management of Schizophrenia Symptoms Using Pharmacological and Non-pharmacological Treatment

Individuals with schizophrenia lead a poor quality of life, due to poor medical attention, homelessness, unemployment, financial constraints, lack of education, and poor social skills. Thus, a review of factors associated with the holistic management of schizophrenia is of paramount importance. The objective of this review is to improve the quality of life of individuals with schizophrenia, by addressing the factors related to the needs of the patients and present them in a unified manner. Although medications play a role, other factors that lead to a successful holistic management of schizophrenia include addressing the following: financial management, independent community living, independent living skill, relationship, friendship, entertainment, regular exercise for weight gained due to medication administration, co-morbid health issues, and day-care programmes for independent living. This review discusses the relationship between different symptoms and problems individuals with schizophrenia face (e.g., homelessness and unemployment), and how these can be managed using pharmacological and non-pharmacological methods. Thus, the target of this review is the carers of individuals with schizophrenia, public health managers, counselors, case workers, psychiatrists, and clinical psychologists aiming to enhance the quality of life of individuals with schizophrenia.

Interactions Between Variation in Candidate Genes and Environmental Factors in the Etiology of Schizophrenia and Bipolar Disorder: a Systematic Review

Schizophrenia and bipolar disorder (BD) are complex and multidimensional disorders with high heritability rates. The contribution of genetic factors to the etiology of these disorders is increasingly being recognized as the action of multiple risk variants with small effect sizes, which might explain only a minor part of susceptibility. On the other site, numerous environmental factors have been found to play an important role in their causality. Therefore, in recent years, several studies focused on gene × environment interactions that are believed to bridge the gap between genetic underpinnings and environmental insults. In this article, we performed a systematic review of studies investigating gene × environment interactions in BD and schizophrenia spectrum phenotypes. In the majority of studies from this field, interacting effects of variation in genes encoding catechol-O-methyltransferase (COMT), brain-derived neurotrophic factor (BDNF), and FK506-binding protein 5 (FKBP5) have been explored. Almost consistently, these studies revealed that polymorphisms in COMT, BDNF, and FKBP5 genes might interact with early life stress and cannabis abuse or dependence, influencing various outcomes of schizophrenia spectrum disorders and BD. Other interactions still require further replication in larger clinical and non-clinical samples. In addition, future studies should address the direction of causality and potential mechanisms of the relationship between gene × environment interactions and various categories of outcomes in schizophrenia and BD.