Cannabinoids for the Treatment of Schizophrenia: An Overview.

“Δ9-tetrahydrocannabinol and its analogues are found to have particular application in psychiatry because of their antipsychotic properties suggesting a therapeutic use as neuroleptic agents in limiting psychotic diseases.

These treatments should not only aim to alleviate specific symptoms but also attempt to delay/arrest disease progression.

In the present review, we reported recent studies supporting the view that the cannabinoid signalling system is a key modulatory element in the activity of the striatum and temporal cortex that has been traditionally associated with psychosis and schizophrenia.

This idea is supported by different anatomical, electrophysiological, pharmacological and biochemical data.

Furthermore, these studies indicate that the cannabinoid system is impaired in different psychotic disorders, supporting the idea of developing novel pharmacotherapies with compounds that selectively target specific elements of the cannabinoid system.”

http://www.ncbi.nlm.nih.gov/pubmed/26845552

http://www.thctotalhealthcare.com/category/schizophrenia/

CB2 Cannabinoid Receptor Knockout in Mice Impairs Contextual Long-Term Memory and Enhances Spatial Working Memory.

“Neurocognitive effects of cannabinoids have been extensively studied with a focus on CB1 cannabinoid receptors because CB1 receptors have been considered the major cannabinoid receptor in the nervous system. However, recent discoveries of CB2 cannabinoid receptors in the brain demand accurate determination of whether and how CB2 receptors are involved in the cognitive effects of cannabinoids.

CB2 cannabinoid receptors are primarily involved in immune functions, but also implicated in psychiatric disorders such as schizophrenia and depression. Here, we examined the effects of CB2 receptor knockout in mice on memory to determine the roles of CB2 receptors in modulating cognitive function.

Our results suggest that CB2 cannabinoid receptors play diverse roles in regulating memory depending on memory types and/or brain areas.”

http://www.ncbi.nlm.nih.gov/pubmed/26819779

The phytocannabinoid, Δ⁹-tetrahydrocannabivarin, can act through 5-HT₁A receptors to produce antipsychotic effects.

“This study aimed to address the questions of whether Δ(9)-tetrahydrocannabivarin (THCV) can (i) enhance activation of 5-HT1 A receptors in vitro and (ii) induce any apparent 5-HT₁A receptor-mediated antipsychotic effects in vivo…

Our findings suggest that THCV can enhance 5-HT₁A receptor activation, and that some of its apparent antipsychotic effects may depend on this enhancement.

We conclude that THCV has therapeutic potential for ameliorating some of the negative, cognitive and positive symptoms of schizophrenia.”

http://www.ncbi.nlm.nih.gov/pubmed/25363799

Endocannabinoids and Mental Disorders.

“Preclinical and clinical data fully support the involvement of the endocannabinoid system in the etiopathogenesis of several mental diseases.

In this review we will briefly summarize the most common alterations in the endocannabinoid system, in terms of cannabinoid receptors and endocannabinoid levels, present in mood disorders (anxiety, posttraumatic stress disorder, depression, bipolar disorder, and suicidality) as well as psychosis (schizophrenia) and autism.

The arising picture for each pathology is not always straightforward; however, both animal and human studies seem to suggest that pharmacological modulation of this system might represent a novel approach for treatment.”

http://www.ncbi.nlm.nih.gov/pubmed/26408164

Abnormalities in neuroendocrine stress response in psychosis: the role of endocannabinoids.

“The aim of this article is to summarize current evidence regarding alterations in the neuroendocrine stress response system and endocannabinoid system and their relationship in psychotic disorders such as schizophrenia.

Exposure to stress is linked to the development of a number of psychiatric disorders including psychosis.

However, the precise role of stress in the development of psychosis and the possible mechanisms that might underlie this are not well understood. Recently the cannabinoid hypothesis of schizophrenia has emerged as a potential line of enquiry.

Endocannabinoid levels are increased in patients with psychosis compared with healthy volunteers; furthermore, they increase in response to stress, which suggests another potential mechanism for how stress might be a causal factor in the development of psychosis.

However, research regarding the links between stress and the endocannabinoid system is in its infancy.

Evidence summarized here points to an alteration in the baseline tone and reactivity of the hypothalamic-pituitary-adrenal (HPA) axis as well as in various components of the endocannabinoid system in patients with psychosis.

Moreover, the precise nature of the inter-relationship between these two systems is unclear in man, especially their biological relevance in the context of psychosis.

Future studies need to simultaneously investigate HPA axis and endocannabinoid alterations both at baseline and following experimental perturbation in healthy individuals and those with psychosis to understand how they interact with each other in health and disease and obtain mechanistic insight as to their relevance to the pathophysiology of schizophrenia.”

Cannabidiol and sodium nitroprusside: two novel neuromodulatory pharmacological interventions to treat and prevent psychosis.

“Since most patients with schizophrenia do not respond properly to treatment, scientific effort has been driven to the development of new compounds acting on pharmacological targets beyond the dopaminergic system.

Therefore, the aim is to review basic and clinical research findings from studies evaluating the effects of cannabidiol (CBD), an inhibitor of the reuptake and metabolism of anandamide and several other effects on nervous system, and sodium nitroprusside, a nitric oxide donor, on the prevention and treatment of psychosis.

Animal and human research supports that CBD and sodium nitroprusside might be effective in the prevention and treatment of psychosis in general and especially in schizophrenia.

The evidence available to date shows that CBD and sodium nitroprusside act in pathways associated with psychotic symptoms and that they may be important agents in the management of prodromal psychotic states and psychosis.

This underscores the relevance of further research on the effects of these agents and others that mediate the activity of the cannabinoid system and of nitric oxide, as well as comparative studies of their antipsychotic effects and those of other antipsychotic drugs currently used to treat schizophrenia.”

http://www.ncbi.nlm.nih.gov/pubmed/26350340

Opioid abuse and hospitalization rates in patients with schizophrenia.

“Substance abuse worsens the course of schizophrenia, but it is not known whether or not there are differences between specific substances concerning their association with the hospitalizations of patients with schizophrenia.

The primary aims of this study were to examine the possible associations between amphetamine, cannabis, and opioid abuse, and the risk of hospitalizations among patients with schizophrenia.

The risk of hospitalizations was significantly higher for opioids when compared with amphetamine or cannabis.

Harmful use or dependence of opioids among patients with schizophrenia is associated with significantly higher risk of hospitalizations than either harmful use or dependence of amphetamine or cannabis.”

http://www.ncbi.nlm.nih.gov/pubmed/26313367

Cannabinoids and Schizophrenia: Risks and Therapeutic Potential.

“The endocannabinoid system has been implicated in psychosis both related and unrelated to cannabis exposure, and studying this system holds potential to increase understanding of the pathophysiology of schizophrenia.

Anandamide signaling in the central nervous system may be particularly important.

Δ9-Tetrahydrocannabinol in cannabis can cause symptoms of schizophrenia when acutely administered, and cannabidiol (CBD), another compound in cannabis, can counter many of these effects.

CBD may have therapeutic potential for the treatment of psychosis following cannabis use, as well as schizophrenia, possibly with better tolerability than current antipsychotic treatments. CBD may also have anti-inflammatory and neuroprotective properties.

Establishing the role of CBD and other CBD-based compounds in treating psychotic disorders will require further human research.”

http://www.ncbi.nlm.nih.gov/pubmed/26311150

http://www.thctotalhealthcare.com/category/schizophrenia/

Does cannabis affect dopaminergic signaling in the human brain? A systematic review of evidence to date.

“While abnormalities in multiple pathways may lead to schizophrenia, an abnormality in dopamine neurotransmission is considered to be the final common abnormality.

One would thus expect cannabis use to be associated with dopamine signaling alterations.

This is the first systematic review of all studies, both observational as well as experimental, examining the acute as well as chronic effect of cannabis or its main psychoactive ingredient, THC, on the dopamine system in man…

In man, there is as yet little direct evidence to suggest that cannabis use affects acute striatal dopamine release or affects chronic dopamine receptor status in healthy human volunteers. ”

http://www.ncbi.nlm.nih.gov/pubmed/26068702