Targeting the Endocannabinoid System in Psychiatric Illness.

Image result for J Clin Psychopharmacol

“Prevalence of psychiatric disorders continues to rise globally, yet remission rates and patient outcome remain less than ideal. As a result, novel treatment approaches for these disorders are necessary to decrease societal economic burden, as well as increase individual functioning.

The recent discovery of the endocannabinoid system has provided an outlet for further research into its role in psychiatric disorders, because efficacy of targeted treatments have been demonstrated in medical illnesses, including cancers, neuropathic pain, and multiple sclerosis.

The present review will investigate the role of the endocannabinoid system in psychiatric disorders, specifically schizophrenia, depressive, anxiety, and posttraumatic stress disorders, as well as attention-deficit hyperactivity disorder.

Controversy remains in prescribing medicinal cannabinoid treatments due to the fear of adverse effects. However, one must consider all potential limitations when determining the safety and tolerability of cannabinoid products, specifically cannabinoid content (ie, Δ-tetrahydrocannabinol vs cannabidiol) as well as study design.

The potential efficacy of cannabinoid treatments in the psychiatric population is an emerging topic of interest that provides potential value going forward in medicine.”

Effectiveness of Cannabidiol Oil for Pediatric Anxiety and Insomnia as Part of Posttraumatic Stress Disorder: A Case Report.

Image result for The Permanente Journal

“Anxiety and sleep disorders are often the result of posttraumatic stress disorder and can contribute to an impaired ability to focus and to demonstration of oppositional behaviors.

CASE PRESENTATION:

These symptoms were present in our patient, a ten-year-old girl who was sexually abused and had minimal parental supervision as a young child under the age of five. Pharmaceutical medications provided partial relief, but results were not long-lasting, and there were major side effects. A trial of cannabidiol oil resulted in a maintained decrease in anxiety and a steady improvement in the quality and quantity of the patient’s sleep.

DISCUSSION:

Cannabidiol oil, an increasingly popular treatment of anxiety and sleep issues, has been documented as being an effective alternative to pharmaceutical medications. This case study provides clinical data that support the use of cannabidiol oil as a safe treatment for reducing anxiety and improving sleep in a young girl with posttraumatic stress disorder.”

https://www.ncbi.nlm.nih.gov/pubmed/27768570

Chronic stress leads to epigenetic dysregulation of neuropeptide-Y and cannabinoid CB1 receptor in the mouse cingulate cortex.

Image result for Neuropharmacology

“Persistent stress triggers a variety of mechanisms, which may ultimately lead to the occurrence of anxiety- and depression-related disorders.

Epigenetic modifications represent a mechanism by which chronic stress mediates long-term effects. Here, we analyzed brain tissue from mice exposed to chronic unpredictable stress (CUS), which induced impaired emotional and nociceptive behaviors.

As endocannabinoid (eCB) and neuropeptide-Y (Npy) systems modulate emotional processes, we hypothesized that CUS may affect these systems through epigenetic mechanisms.

We found reduced Npy expression and Npy type 1 receptor (Npy1r) signaling, and decreased expression of the cannabinoid type 1 receptor (CB1) in the cingulate cortex of CUS mice specifically in low CB1-expressing neurons.

Our findings suggest that epigenetic alterations in the Npy and CB1 genes represent one of the potential mechanisms contributing to the emotional imbalance induced by CUS in mice, and that the Npy and eCB systems may represent therapeutic targets for the treatment of psychopathologies associated with or triggered by chronic stress states.”

https://www.ncbi.nlm.nih.gov/pubmed/27737789

Cannabinoid CB1 receptors in distinct circuits of the extended amygdala determine fear responsiveness to unpredictable threat.

Image result for Mol Psychiatry.

“The brain circuits underlying behavioral fear have been extensively studied over the last decades.

Here, we show that the endocannabinoid system acting in synaptic circuits of the extended amygdala can explain the fear response profile during exposure to unpredictable threat.

Using fear training with predictable or unpredictable cues in mice, combined with local and cell-type-specific deficiency and rescue of cannabinoid type 1 (CB1) receptors, we found that presynaptic CB1 receptors on distinct amygdala projections to bed nucleus of the stria terminalis (BNST) are both necessary and sufficient for the shift from phasic to sustained fear in response to an unpredictable threat.

These results thereby identify the causal role of a defined protein in a distinct brain pathway for the temporal development of a sustained state of anxious apprehension during unpredictability of environmental influences, reminiscent of anxiety symptoms in humans.”

https://www.ncbi.nlm.nih.gov/pubmed/27698427

Endocannabinoid signaling in social functioning: an RDoC perspective.

Image result for Transl Psychiatry.

“Core deficits in social functioning are associated with various neuropsychiatric and neurodevelopmental disorders, yet biomarker identification and the development of effective pharmacological interventions has been limited.

Recent data suggest the intriguing possibility that endogenous cannabinoids, a class of lipid neuromodulators generally implicated in the regulation of neurotransmitter release, may contribute to species-typical social functioning.

Systematic study of the endogenous cannabinoid signaling could, therefore, yield novel approaches to understand the neurobiological underpinnings of atypical social functioning.

This article provides a critical review of the major components of the endogenous cannabinoid system (for example, primary receptors and effectors-Δ9-tetrahydrocannabinol, cannabidiol, anandamide and 2-arachidonoylglycerol) and the contributions of cannabinoid signaling to social functioning.

Data are evaluated in the context of Research Domain Criteria constructs (for example, anxiety, chronic stress, reward learning, motivation, declarative and working memory, affiliation and attachment, and social communication) to enable interrogation of endogenous cannabinoid signaling in social functioning across diagnostic categories.

The empirical evidence reviewed strongly supports the role for dysregulated cannabinoid signaling in the pathophysiology of social functioning deficits observed in brain disorders, such as autism spectrum disorder, schizophrenia, major depressive disorder, posttraumatic stress disorder and bipolar disorder.

Moreover, these findings indicate that the endogenous cannabinoid system holds exceptional promise as a biological marker of, and potential treatment target for, neuropsychiatric and neurodevelopmental disorders characterized by impairments in social functioning.”

https://www.ncbi.nlm.nih.gov/pubmed/27676446

Don’t Worry, Be Happy: Endocannabinoids and Cannabis at the Intersection of Stress and Reward.

Image result for annual review of pharmacology and toxicology

“Cannabis enables and enhances the subjective sense of well-being by stimulating the endocannabinoid system (ECS), which plays a key role in modulating the response to stress, reward, and their interactions.

The recent shift toward legalization of medical or recreational cannabis has renewed interest in investigating the physiological role of the ECS as well as the potential health effects, both adverse and beneficial, of cannabis.

Here we review our current understanding of the ECS and its complex physiological roles.

We discuss the implications of this understanding vis-á-vis the ECS’s modulation of stress and reward and its relevance to mental disorders in which these processes are disrupted (i.e., addiction, depression, posttraumatic stress disorder, schizophrenia), along with the therapeutic potential of strategies to manipulate the ECS for these conditions.”

http://www.ncbi.nlm.nih.gov/pubmed/27618739

Modulation of Long-Term Potentiation of Cortico-Amygdala Synaptic Responses and Auditory Fear Memory by Dietary Polyunsaturated Fatty Acid.

Image result for Front Behav Neurosci

“Converging evidence suggests that an imbalance of ω3 to ω6 polyunsaturated fatty acid (PUFA) in the brain is involved in mental illnesses such as anxiety disorders.

We previously reported that the dietary ratio of ω3 to ω6 PUFA alters this ratio in the brain, and influences contextual fear memory.

In addition to behavioral change, enhancement of cannabinoid CB1 receptor-mediated short-term synaptic plasticity and facilitation of the agonist sensitivity of CB1 receptors have been observed in excitatory synaptic responses in the basolateral nucleus of the amygdala (BLA).

These results suggest that the balance of ω3 to ω6 PUFA has an impact on fear memory and cortico-amygdala synaptic plasticity, both in a CB1 receptor-dependent manner.”

Dorsal hippocampus cannabinoid type 1 receptors modulate the expression of contextual fear conditioning in rats: Involvement of local glutamatergic/nitrergic and GABAergic neurotransmissions.

Image result for Eur Neuropsychopharmacol.

“The cannabinoid receptor type 1 (CB1) is highly expressed in the dorsal portion of hippocampus – a brain region that has been involved in the control of conditioned emotional response (CER) in the contextual fear conditioning (CFC) model.

These responses are characterized by increased freezing behavior and autonomic parameters. Moreover, CB1 receptors activation negatively modulate the release of several neurotransmitters, including glutamate and GABA, which also have been related to modulation of CER. Therefore, our aim was to investigate the involvement of CB1 receptors in the dorsal hippocampus on CER expression.

Our results suggest that increased CER evoked by CB1 blockade in the dorsal hippocampus depends on NMDA receptor activation and NO formation. Moreover, a fine-tune control promoted by GABAergic and glutamatergic mechanisms in this brain area modulate the CER after CB1 blockade.”

http://www.ncbi.nlm.nih.gov/pubmed/27591981

Cannabinoids and post-traumatic stress disorder: clinical and preclinical evidence for treatment and prevention.

“There is substantial evidence from studies in humans and animal models for a role of the endocannabinoid system in the control of emotional states. Several studies have shown an association between exposure to trauma and substance use. Specifically, it has been shown that there is increased prevalence of cannabis use in post-traumatic stress disorder (PTSD) patients and vice versa.

Clinical studies suggest that PTSD patients may cope with their symptoms by using cannabis. This treatment-seeking strategy may explain the high prevalence of cannabis use among individuals with PTSD.

Preliminary studies in humans also suggest that treatment with cannabinoids may decrease PTSD symptoms including sleep quality, frequency of nightmares, and hyperarousal.

Studies in animal models have shown that cannabinoids can prevent the effects of stress on emotional function and memory processes, facilitate fear extinction, and have an anti-anxiety-like effect in a variety of tasks.

Moreover, cannabinoids administered shortly after exposure to a traumatic event were found to prevent the development of PTSD-like phenotype.

In this article, we review the existing literature on the use of cannabinoids for treating and preventing PTSD in humans and animal models.

There is a need for large-scale clinical trials examining the potential decrease in PTSD symptomatology with the use of cannabis.

In animal models, there is a need for a better understanding of the mechanism of action and efficacy of cannabis. Nevertheless, the end result of the current clinical and preclinical data is that cannabinoid agents may offer therapeutic benefits for PTSD.”

http://www.ncbi.nlm.nih.gov/pubmed/27551883

Peripheral and central CB1 cannabinoid receptors control stress-induced impairment of memory consolidation.

“Stressful events can generate emotional memories linked to the traumatic incident, but they also can impair the formation of nonemotional memories. Although the impact of stress on emotional memories is well studied, much less is known about the influence of the emotional state on the formation of nonemotional memories.

We used the novel object-recognition task as a model of nonemotional memory in mice to investigate the underlying mechanism of the deleterious effect of stress on memory consolidation.

Systemic, hippocampal, and peripheral blockade of cannabinoid type-1 (CB1) receptors abolished the stress-induced memory impairment. Genetic deletion and rescue of CB1 receptors in specific cell types revealed that the CB1 receptor population specifically in dopamine β-hydroxylase (DBH)-expressing cells is both necessary and sufficient for stress-induced impairment of memory consolidation, but CB1 receptors present in other neuronal populations are not involved.

Strikingly, pharmacological manipulations in mice expressing CB1 receptors exclusively in DBH+ cells revealed that both hippocampal and peripheral receptors mediate the impact of stress on memory consolidation.

Thus, CB1 receptors on adrenergic and noradrenergic cells provide previously unrecognized cross-talk between central and peripheral mechanisms in the stress-dependent regulation of nonemotional memory consolidation, suggesting new potential avenues for the treatment of cognitive aspects on stress-related disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/27528659