“Anxiety and anxiety-like disorders describe many mental disorders, yet fear is a common overwhelming symptom often leading to depression. Currently two basic strategies are discussed to treat anxiety: pharmacotherapy or psychotherapy. In the pharmacotherapeutical clinical approach, several conventional synthetic anxiolytic drugs are being used with several adverse effects. Therefore, studies to find suitable safe medicines from natural sources are being sought by researchers. The results of a plethora experimental studies demonstrated that dietary phytochemicals like alkaloids, terpenes, flavonoids, phenolic acids, lignans, cinnamates, and saponins or various plant extracts with the mixture of different phytochemicals possess anxiolytic effects in a wide range of animal models of anxiety. The involved mechanisms of anxiolytics action include interaction with γ-aminobutyric acid A receptors at benzodiazepine (BZD) and non-BZD sites with various affinity to different subunits, serotonergic 5-hydrodytryptamine receptors, noradrenergic and dopaminergic systems, glutamate receptors, and cannabinoid receptors. This review focuses on the use of both plant-derived natural compounds and plant extracts with anxiolytic effects, describing their biological effects and clinical application.”
“Ample evidence demonstrates that fear learning contributes significantly to many anxiety pathologies including post-traumatic stress disorder (PTSD). The endocannabinoid (eCB) system may offer therapeutic benefits for PTSD and it is a modulator of the hypothalamic pituitary adrenal (HPA) axis.
Here we compared the separated and combined effects of blocking glucocorticoid receptors (GRs) using the GR antagonist RU486 and enhancing CB1r signaling using the CB1/2 receptor agonist WIN55,212-2 in the CA1 and basolateral amygdala (BLA) on the consolidation of traumatic memory. Traumatic memory was formed by exposure to a severe footshock in an inhibitory avoidance apparatus followed by exposure to trauma reminders. Intra-BLA RU486 (10 ng/side) and WIN55,212-2 (5 μg/side) administered immediately after shock exposure dampened the consolidation of the memory about the traumatic event and attenuated the increase in acoustic startle response in rats exposed to shock and reminders. In the CA1, WIN55,212-2 impaired consolidation and attenuated the increase in acoustic startle response whereas RU486 had no effect. The effects of WIN55,212-2 were found to be mediated by CB1 receptors, but not by GRs. Moreover, post-shock systemic WIN55,212-2 (0.5 mg/kg) administration prevented the increase in GRs and CB1 receptor levels in the CA1 and BLA in rats exposed to shock and reminders.
The findings suggest that the BLA is a locus of action of cannabinoids and glucocorticoids in modulating consolidation of traumatic memory in a rat model of PTSD. Also, the findings highlight novel targets for the treatment of emotional disorders and PTSD in particular.”
“Exposure to stress is an undeniable, but in most cases surmountable, part of life. However, in certain individuals, exposure to severe or cumulative stressors can lead to an array of pathological conditions including posttraumatic stress disorder (PTSD), characterized by debilitating trauma-related intrusive thoughts, avoidance behaviors, hyperarousal, as well as depressed mood and anxiety.
In the context of the rapidly changing political and legal landscape surrounding use of cannabis products in the United States, there has been a surge of public and research interest in the role of cannabinoids in the regulation of stress-related biological processes and in their potential therapeutic application for stress-related psychopathology.
Here we review the current state of knowledge regarding the effects of cannabis and cannabinoids in PTSD and the preclinical and clinical literature on the effects of cannabinoids and endogenous cannabinoid signaling systems in the regulation of biological processes related to the pathogenesis of PTSD.
Potential therapeutic implications of the reviewed literature are also discussed. Lastly, we propose that a state of endocannabinoid deficiency could represent a stress-susceptibility endophenotype predisposing to the development of trauma-related psychopathology and provide biologically plausible support for the self-medication hypotheses used to explain high rates of cannabis use in patients with trauma-related disorders.”
“Limited efficacy for current pharmacotherapy for PTSD indicates that improved pharmacological treatments are needed. Neurobiological research points to cannabinoids as possible therapeutic agents of interest. Moreover, observational reports indicate that there is growing popular interest in therapeutic use of cannabinoids for the alleviation of trauma symptoms. The aim of this review was to present an up-to-date look at current research on the possible therapeutic value of cannabinoids for PTSD. Experimental, preclinical, and clinical findings are discussed.
Neurobiological research indicates cannabis as possible pharmacological intervention for PTSD.
CBD and THC + CBD modulate fear memory in rodents.
Experimental data suggest CBD has acute anti-depressive and anxiolytic effects.
Data suggest THC reduces nightmares and OSA, while THC + CBD could reduce insomnia.
Randomized placebo-controlled human trials of cannabinoids for PTSD are underway.”
“Exposure to excessive or uncontrolled stress is a major factor associated with various diseases including post-traumatic stress disorder (PTSD). The consequences of exposure to trauma are affected not only by aspects of the event itself, but also by the frequency and severity of trauma reminders. It was suggested that in PTSD, hippocampal-dependent memory is compromised while amygdala-dependent memory is strengthened.
Several lines of evidence support the role of the endocannabinoid (eCB) system as a modulator of the stress response.
In this study we aimed to examine cannabinoids modulation of the long-term effects (i.e., 1 month) of exposure to a traumatic event on memory and plasticity in the hippocampus and amygdala.
Cannabinoids prevent the differential long-term effects of exposure to severe stress on hippocampal- and amygdala-dependent memory and plasticity.
Taken together, these findings suggest the involvement of the endocannabinoid system, and specifically CB1 receptors, in the opposite effects of severe stress on memory and plasticity in the hippocampus and amygdala.” https://www.ncbi.nlm.nih.gov/pubmed/28667676
“In the past two decades, there has been increasing interest in the therapeutic potential of cannabis and single cannabinoids, mainly cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC). THC and cannabis products rich in THC exert their effects mainly through the activation of cannabinoid receptors (CB1 and CB2). Since 1975, 140 controlled clinical trials using different cannabinoids or whole-plant preparations for the treatment of a large number of disorders and symptoms have been conducted. Results have led to the approval of cannabis-based medicines [dronabinol, nabilone, and the cannabis extract nabiximols (Sativex®, THC:CBD = 1:1)] as well as cannabis flowers in several countries. Controlled clinical studies provide substantial evidence for the use of cannabinoid receptor agonists in cancer chemotherapy induced nausea and vomiting, appetite loss and cachexia in cancer and HIV patients, neuropathic and chronic pain, and in spasticity in multiple sclerosis. In addition, there is also some evidence suggesting a therapeutic potential of cannabis-based medicines in other indications including Tourette syndrome, spinal cord injury, Crohn’s disease, irritable bowel syndrome, and glaucoma. In several other indications, small uncontrolled and single-case studies reporting beneficial effects are available, for example in posttraumatic stress disorder, attention deficit hyperactivity disorder, and migraine. The most common side effects of THC and cannabis-based medicines rich in THC are sedation and dizziness (in more than 10% of patients), psychological effects, and dry mouth. Tolerance to these side effects nearly always develops within a short time. Withdrawal symptoms are hardly ever a problem in the therapeutic setting. In recent years there is an increasing interest in the medical use of CBD, which exerts no intoxicating side effects and is usually well-tolerated. Preliminary data suggest promising effects in the treatment of anxiety disorders, schizophrenia, dystonia, and some forms of epilepsy. This review gives an overview on clinical studies which have been published over the past 40 years.”
“The endocannabinoid (eCB) system has attracted attention for its role in various behavioral and brain functions, and as a therapeutic target in neuropsychiatric disease states, including anxiety disorders and other conditions resulting from dysfunctional responses to stress. In this mini-review, we highlight components of the eCB system that offer potential ‘druggable’ targets for new anxiolytic medications, emphasizing some of the less well-discussed options. We discuss how selectively amplifying eCBs recruitment by interfering with eCB-degradation, via fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), has been linked to reductions in anxiety-like behaviors in rodents and variation in human anxiety symptoms. We also discuss a non-canonical route to regulate eCB degradation that involves interfering with cyclooxygenase-2 (COX-2). Next, we discuss approaches to targeting eCB receptor-signaling in ways that do not involve the cannabinoid receptor subtype 1 (CB1R); by targeting the CB2R subtype and the transient receptor potential vanilloid type 1 (TRPV1). Finally, we review evidence that cannabidiol (CBD), while representing a less specific pharmacological approach, may be another way to modulate eCBs and interacting neurotransmitter systems to alleviate anxiety. Taken together, these various approaches provide a range of plausible paths to developing novel compounds that could prove useful for treating trauma-related and anxiety disorders.”
“Stress is a ubiquitous risk factor for the exacerbation and development of affective disorders including major depression and posttraumatic stress disorder. Understanding the neurobiological mechanisms conferring resilience to the adverse consequences of stress could have broad implications for the treatment and prevention of mood and anxiety disorders. We utilize laboratory mice and their innate inter-individual differences in stress-susceptibility to demonstrate a critical role for the endogenous cannabinoid 2-arachidonoylglycerol (2-AG) in stress-resilience. Specifically, systemic 2-AG augmentation is associated with a stress-resilient phenotype and enhances resilience in previously susceptible mice, while systemic 2-AG depletion or CB1 receptor blockade increases susceptibility in previously resilient mice. Moreover, stress-resilience is associated with increased phasic 2-AG-mediated synaptic suppression at ventral hippocampal-amygdala glutamatergic synapses and amygdala-specific 2-AG depletion impairs successful adaptation to repeated stress. These data indicate amygdala 2-AG signalling mechanisms promote resilience to adverse effects of acute traumatic stress and facilitate adaptation to repeated stress exposure.” https://www.ncbi.nlm.nih.gov/pubmed/28348378
“Natural cannabinoid found to play key role in anxiety. Stress-related mood and anxiety disorders affect millions of people in the United States. A new study examines the neurobiology behind these illnesses and finds that controlling a molecule that activates cannabinoid receptors can reduce the symptoms of anxiety.” http://www.medicalnewstoday.com/articles/316682.php
“Learning to associate cues or contexts with potential threats or rewards is adaptive and enhances survival. Both aversive and appetitive memories are therefore powerful drivers of behaviour but the inappropriate expression of conditioned responding to fear- and drug-related stimuli can develop into anxiety-related and substance abuse disorders, respectively. These disorders are associated with abnormally persistent emotional memories and inadequate treatment, often leading to symptom relapse.
Studies show that cannabidiol, the main non-psychotomimetic phytocannabinoid found in Cannabis sativa, reduces anxiety via serotonin1A and (indirect) cannabinoid receptor activation in paradigms assessing innate responses to threat.
Accumulating evidence from animal studies investigating the effects of cannabidiol on fear memory processing also indicates that it reduces learned fear in paradigms that are translationally relevant to phobias and post-traumatic stress disorder.
Cannabidiol does so by reducing fear expression acutely, and by disrupting fear memory reconsolidation and enhancing fear extinction, both of which can result in the lasting reduction of learned fear.
Recent studies have also begun to determine the effects of cannabidiol on drug memory expression using paradigms with translational relevance to addiction. Emerging evidence suggests that cannabidiol reduces the expression of drug memories acutely and by disrupting their reconsolidation.
Here we review the literature demonstrating the anxiolytic effects of cannabidiol before focusing on studies investigating its effects on various fear and drug memory processes. Understanding how cannabidiol regulates emotion and emotional memory processing may eventually lead to its use in treating anxiety-related and substance abuse disorders.”