Cannabidiol, neuroprotection and neuropsychiatric disorders.

“Cannabidiol (CBD) is a non-psychotomimetic phytocannabinoid derived from Cannabis sativa.

It has possible therapeutic effects over a broad range of neuropsychiatric disorders.

CBD attenuates brain damage associated with neurodegenerative and/or ischemic conditions.

It also has positive effects on attenuating psychotic-, anxiety- and depressive-like behaviors.

Moreover, CBD affects synaptic plasticity and facilitates neurogenesis.

The mechanisms of these effects are still not entirely clear but seem to involve multiple pharmacological targets.

In the present review, we summarized the main biochemical and molecular mechanisms that have been associated with the therapeutic effects of CBD, focusing on their relevance to brain function, neuroprotection and neuropsychiatric disorders.”

http://www.ncbi.nlm.nih.gov/pubmed/26845349

A systematic review of plant-derived natural compounds for anxiety disorders.

“Anxiety disorders are the most common mental illnesses affecting human beings. They range from panic to generalized anxiety disorders upsetting the well-being and psychosocial performance of patients. Several conventional anxiolytic drugs are being used which in turn result in several adverse effects. Therefore, studies to find suitable safe medicines from natural sources are being conducted by researchers.

The aim of the present study is to comprehensively review phytochemical compounds with well-established anxiolytic activities and their structure-activity relationships as well as neuropsychopharmacological aspects. Results showed that phytochemicals like; alkaloids, flavonoids, phenolic acids, lignans, cinnamates, terpenes and saponins possess anxiolytic effects in a wide range of animal models of anxiety.

The involved mechanisms include interaction with γ-aminobutyric acid (GABA)A receptors at benzodiazepine (BZD) and non-BZD sites with various affinity to different subunits, serotonergic 5-hydrodytryptamine (5-HT)1A and 5-HT2A/C receptors, noradrenergic and dopaminergic systems, glycine and glutamate receptors, and κ-opioid receptor as well as cannabinoid (CB)1 and CB2 receptors.

Phytochemicals also modulate the hypothalamo-pituitary-adrenal (HPA) axis, the levels of pro-inflammatory cytokines like interleukin (IL)-2, IL-6, IL-1β and tumor necrosis factor (TNF)-α, and improve brain derived neurotrophic factor (BDNF) levels. Transient receptor potential cation channel subfamily V (TRPV)3, nitric oxide cyclic guanosine monophosphate (NO-cGMP) pathway and monoamine oxidase enzymes are other targets of phytochemicals with anxiolytic activity.

Taking together, these phytochemicals may be considered as supplements to conventional anxiolytic therapies in order to improve efficacy and reduce adverse effects.

Further preclinical and clinical studies are still needed in order to recognize the structure-activity relationships, metabolism, absorption, and neuropsychopharmacological mechanisms of plant-derived natural agents.”

http://www.ncbi.nlm.nih.gov/pubmed/26845556

The association between cannabis use and anxiety disorders: Results from a population-based representative sample.

“This study explored the association between cannabis use, cannabis use disorders (CUDs) and anxiety disorders in a 3-year prospective study.

Our findings suggest that cannabis use and CUDs are not associated with increased incidence of most anxiety disorders and inversely, most anxiety disorders are not associated with increased incidence of cannabis use or CUDs.”

http://www.ncbi.nlm.nih.gov/pubmed/26775742

Cannabis use, depression and anxiety: A 3-year prospective population-based study.

“Whether or not cannabis use may increase the risk for depression and/or anxiety is not clear. For one thing, it has not been possible to draw a definitive conclusion regarding the direction of causality, i.e. whether cannabis use increases the risk for depression/anxiety or vice versa. This study aimed at examining possible associations between cannabis use, depression and anxiety, using all three measures as both exposure and outcome…

CONCLUSIONS:

We found no longitudinal associations between cannabis use and incidence of depression/anxiety, or between depression/anxiety and later cannabis use onset.”

http://www.ncbi.nlm.nih.gov/pubmed/26773900

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