Self-Medication of Somatic and Psychiatric Conditions Using Botanical Marijuana.

“As a complement to research evaluating botanical marijuana as a medical therapy for various somatic and psychiatric conditions, there is a growing body of research assessing marijuana users’ self-reports of the symptoms and conditions for which they use marijuana without a physician’s recommendation.

As part of two larger web-based surveys and one in-situ survey at an outdoor marijuana festival, we asked regular marijuana users if they consumed the drug without a physician’s recommendation and, if so, to describe (or select from a checklist) the conditions for which they used marijuana as a medication.

Participants reported using marijuana to self-medicate a wide variety of both somatic conditions (such as pain, diabetes, and irritable bowel syndrome) and psychiatric conditions (such as depression, anxiety, and insomnia).

Because fewer than half of the American states, and only a few countries, allow physicians to recommend medicinal marijuana, these findings may be of interest to clinicians as they treat patients, to lawmakers and policymakers as they consider legislation allowing physicians to recommend botanical marijuana for somatic and psychiatric conditions, and to researchers evaluating conditions that individuals elect to self-medicate using botanical marijuana.”

http://www.ncbi.nlm.nih.gov/pubmed/26595140

The endocannabinoid system in guarding against fear, anxiety and stress.

“The endocannabinoid (eCB) system has emerged as a central integrator linking the perception of external and internal stimuli to distinct neurophysiological and behavioural outcomes (such as fear reaction, anxiety and stress-coping), thus allowing an organism to adapt to its changing environment.

eCB signalling seems to determine the value of fear-evoking stimuli and to tune appropriate behavioural responses, which are essential for the organism’s long-term viability, homeostasis and stress resilience; and dysregulation of eCB signalling can lead to psychiatric disorders.

An understanding of the underlying neural cell populations and cellular processes enables the development of therapeutic strategies to mitigate behavioural maladaptation.”

http://www.ncbi.nlm.nih.gov/pubmed/26585799

Targeting the endocannabinoid system to treat anxiety-related disorders.

“The endocannabinoid system plays an important role in the control of emotions, and its dysregulation has been implicated in several psychiatric disorders.

The most common self-reported reason for using cannabis is rooted in its ability to reduce feelings of stress, tension, and anxiety.

Nevertheless, there are only few studies in controlled clinical settings that confirm that administration of cannabinoids can benefit patients with a post-traumatic stress disorder (PTSD).

There are considerable encouraging preclinical data to suggest that endocannabinoid-targeted therapeutics for anxiety disorders should continue.

In this review, we will describe data supporting a role for the endocannabinoid system in preventing and treating anxiety-like behavior in animal models and PTSD patients.

Cannabinoids have shown beneficial outcomes in rat and mouse models of anxiety and PTSD, but they also may have untoward effects that discourage their chronic usage, including anxiogenic effects.

Hence, clinical and preclinical research on the endocannabinoid system should further study the effects of cannabinoids on anxiety and help determine whether the benefits of using exogenous cannabinoids outweigh the risks.

In general, this review suggests that targeting the endocannabinoid system represents an attractive and novel approach to the treatment of anxiety-related disorders and, in particular, PTSD.”

http://www.ncbi.nlm.nih.gov/pubmed/26426887

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

Cannabinoid receptor activation in the basolateral amygdala blocks the effects of stress on the conditioning and extinction of inhibitory avoidance.

“The endocannabinoid system has recently emerged as important in the regulation of extinction learning and in the regulation of the hypothalamic-pituitary-adrenal axis.

Here, we aimed to examine the involvement of the cannabinoid CB(1) receptor in the basolateral amygdala (BLA) in inhibitory avoidance (IA) conditioning and extinction and to test whether cannabinoid activation would reverse the effects of stress on these memory processes.

Together, our findings may support a wide therapeutic application for cannabinoids in the treatment of conditions associated with the inappropriate retention of aversive memories and stress-related disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/19741114

Cannabinoid type-1 receptor signaling in central serotonergic neurons regulates anxiety-like behavior and sociability.

“The endocannabinoid (eCB) system possesses neuromodulatory functions by influencing the release of various neurotransmitters, including γ-aminobutyric acid (GABA) and glutamate. A functional interaction between eCBs and the serotonergic system has already been suggested.

Previously, we showed that cannabinoid type-1 (CB1) receptor mRNA and protein are localized in serotonergic neurons of the raphe nuclei, implying that the eCB system can modulate serotonergic functions.

In order to substantiate the physiological role of the CB1 receptor in serotonergic neurons of the raphe nuclei, we generated serotonergic 5-hydroxytryptamine (5-HT) neuron-specific CB 1 receptor-deficient mice, using the Cre/loxP system with a tamoxifen-inducible Cre recombinase under the control of the regulatory sequences of the tryptophan hydroxylase 2 gene (TPH2-CreER (T2)), thus, restricting the recombination to 5-HT neurons of the central nervous system (CNS).

Applying several different behavioral paradigms, we revealed that mice lacking the CB1 receptor in serotonergic neurons are more anxious and less sociable than control littermates. Thus, we were able to show that functional CB1 receptor signaling in central serotonergic neurons modulates distinct behaviors in mice.”

http://www.ncbi.nlm.nih.gov/pubmed/26388750

Potential Therapeutic Value of a Novel FAAH Inhibitor for the Treatment of Anxiety.

“Anxiety disorders are among the most prevalent psychiatric diseases with high personal costs and a remarkable socio-economic burden. However, current treatment of anxiety is far from satisfactory.

Novel pharmacological targets have emerged in the recent years, and attention has focused on the endocannabinoid (eCB) system, given the increasing evidence that supports its central role in emotion, coping with stress and anxiety.

In the management of anxiety disorders, drug development strategies have left apart the direct activation of type-1 cannabinoid receptors to indirectly enhance eCB signalling through the inhibition of eCB deactivation, that is, the inhibition of the fatty acid amide hydrolase (FAAH) enzyme.

In the present study, we provide evidence for the anxiolytic-like properties of a novel, potent and selective reversible inhibitor of FAAH, ST4070, orally administered to rodents.

Altogether, ST4070 offers a promising anxiolytic-like profile in preclinical studies, although further studies are warranted to clearly demonstrate its efficacy in the clinic management of anxiety disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26360704

Cannabidiol as a Potential Treatment for Anxiety Disorders.

“Cannabidiol (CBD), a Cannabis sativa constituent, is a pharmacologically broad-spectrum drug that in recent years has drawn increasing interest as a treatment for a range of neuropsychiatric disorders.

The purpose of the current review is to determine CBD’s potential as a treatment for anxiety-related disorders, by assessing evidence from preclinical, human experimental, clinical, and epidemiological studies.

We found that existing preclinical evidence strongly supports CBD as a treatment for generalized anxiety disorder, panic disorder, social anxiety disorder, obsessive-compulsive disorder, and post-traumatic stress disorder when administered acutely; however, few studies have investigated chronic CBD dosing.

Likewise, evidence from human studies supports an anxiolytic role of CBD, but is currently limited to acute dosing, also with few studies in clinical populations.

Overall, current evidence indicates CBD has considerable potential as a treatment for multiple anxiety disorders, with need for further study of chronic and therapeutic effects in relevant clinical populations.”

http://www.ncbi.nlm.nih.gov/pubmed/26341731

The endocannabinoid, endovanilloid and nitrergic systems could interact in the rat dorsolateral periaqueductal gray matter to control anxiety-like behaviors.

“Cannabinoid compounds usually produce biphasic effects in the modulation of emotional responses.

Low doses of the endocannabinoid anandamide (AEA) injected into the dorsolateral periaqueductal gray matter (dlPAG) induce anxiolytic-like effects via CB1 receptors activation.

However, at higher doses the drug loses this effect, in part by activating Transient Receptor Potential Vanilloid Type 1 (TRPV1).

Activation of these latter receptors could induce the formation of nitric oxide (NO). Thus, the present study tested the hypothesis that at high doses AEA loses it anxiolytic-like effect by facilitating, probably via TRPV1 receptor activation, the formation of NO.

…these results support the hypothesis that intra-dlPAG injections of high doses of AEA lose their anxiolytic effects by favoring TRPV1 receptors activity and consequent NO formation, which in turn could facilitate defensive responses.”

Neurobiological Interactions Between Stress and the Endocannabinoid System.

“Stress affects a constellation of physiological systems in the body and evokes a rapid shift in many neurobehavioral processes.

A growing body of work indicates that the endocannabinoid (eCB) system is an integral regulator of the stress response.

In the current review, we discuss the evidence to date that demonstrates stress-induced regulation of eCB signaling and the consequential role changes in eCB signaling play with respect to many of the effects of stress.

Across a wide array of stress paradigms, studies have generally shown that stress evokes bidirectional changes in the two eCB molecules, anandamide (AEA) and 2-arachidonoyl glycerol (2-AG), with stress exposure reducing AEA levels and increasing 2-AG levels.

Additionally, in almost every brain region examined, exposure to chronic stress reliably causes a down-regulation or loss of cannabinoid type 1 (CB1) receptors.

With respect to the functional role of changes in eCB signaling during stress, studies have demonstrated that the decline in AEA appears to contribute to the manifestation of the stress response, including activation of the hypothalamic-pituitary-adrenal (HPA) axis and increases in anxiety behavior, while the increased 2-AG signaling contributes to termination and adaptation of the HPA axis, as well as potentially contributing to changes in pain perception and synaptic plasticity.

More so, translational studies have shown that eCB signaling in humans regulates many of the same domains and appears to be a critical component of stress regulation, and impairments in this system may be involved in the vulnerability to stress-related psychiatric conditions, such as depression and post-traumatic stress disorder.

Collectively, these data create a compelling argument that eCB signaling is an important regulatory system in the brain that largely functions to buffer against many of the effects of stress and that dynamic changes in this system contribute to different aspects of the stress response.”

http://www.ncbi.nlm.nih.gov/pubmed/26068727