An endocannabinoid mechanism in relapse to drug seeking: a review of animal studies and clinical perspectives.

Abstract

“Detoxification from drug abuse is strongly threatened by the occurrence of renewed episodes of drug intake. In human addicts, relapse to drug seeking may take place even after a considerably long period from the last drug consumption. Over the last decade, the endocannabinoid system has received remarkable attention due to its unique features, including its rewarding properties closely resembling those of the most commonly abused substances and its multiple therapeutic implications. Although limited at present, evidence is now emerging on a possible participation of the endogenous cannabinoid system in the regulation of relapsing phenomena. Both stimulation and blockade of the central cannabinoid CB-sub1 receptor have proved to play an important role in drug- as well as in cue-induced reinstatement of drug seeking behavior. Indeed, while CB-sub1 receptor stimulation may elicit relapse not only to cannabinoid seeking but also to cocaine, heroin, alcohol and methamphetamine, this effect is significantly attenuated, when not fully prevented, by pretreatment with the CB-sub1 receptor antagonist rimonabant. However, corroborating data on the involvement of the cannabinoid system in stress-induced reinstatement are still rather scarce. The present review attempts to collect data obtained from different laboratories using diverse experimental approaches, to provide a comprehensive picture of the recent evidence of a relationship between the cannabinoid system and the neurobiological mechanisms leading to relapse. For each class of abused drugs, the conspicuous progress made in delineating the role of the endocannabinoid system in relapse to drug seeking has been examined by placing particular emphasis on the findings obtained from behavioral studies. After summarizing findings and implications emerging from the reviewed studies, we conclude by briefly discussing what information is still missing and how missing information might be obtained.”

http://www.ncbi.nlm.nih.gov/pubmed/16839608

Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug

“The use Cannabis sativa(cannabis) extracts as medicine was described in China and India before the birth of Christ. The therapeutic use of cannabis was introduced in Western medicine in the first half of the 19th century and reached its climax in the last two decades of the same century. At the turn of the century, several pharmaceutical companies were marketing cannabis extracts and tinctures which were prescribed by doctors for many different complaints including pain, whooping cough and asthma, and as a sedative/hypnotic agent. However, the use of cannabis as a medicine almost completely disappeared at about the middle of the 20th century. The main reasons for this disappearance were the variable potency of cannabis extracts, the erratic and unpredictable individual responses, the introduction of synthetic and more stable pharmaceutical substitutes such as aspirin, chloral hydrate and barbiturates, the recognition of important adverse effects such as anxiety and cognitive impairment, and the legal restrictions to the use of cannabis-derived medicines .”

“Today this situation has changed considerably. The main active psychotropic constituent of cannabis, D9-tetrahydrocannabinol (D9-THC), was isolated, identified and synthesized in the 1960’s. Almost three decades later, cannabinoid receptors in the brain were described and cloned and the endogenous cannabinoids were isolated and identified. As a result of these discoveries the interest in cannabis research has remarkably increased. For instance, the number of publications using the key word “brain”, compiled by the ISI Web of Knowledge, increased 26 times from 1960-1964 to 2000-2004, while the number of publications about `cannabis’ increased 78.5 times during the same period. As a consequence, the research on the use of cannabis as medicine has been renewed.”

” A high dose of D9-tetrahydrocannabinol, the main Cannabis sativa (cannabis) component, induces anxiety and psychotic-like symptoms in healthy volunteers. These effects of D9-tetrahydrocannabinol are significantly reduced by cannabidiol (CBD), a cannabis constituent which is devoid of the typical effects of the plant. This observation led us to suspect that CBD could have anxiolytic and/or antipsychotic actions. Studies in animal models and in healthy volunteers clearly suggest an anxiolytic-like effect of CBD. The antipsychotic-like properties of CBD have been investigated in animal models using behavioral and neurochemical techniques which suggested that CBD has a pharmacological profile similar to that of atypical antipsychotic drugs. The results of two studies on healthy volunteers using perception of binocular depth inversion and ketamine-induced psychotic symptoms supported the proposal of the antipsychotic-like properties of CBD. In addition, open case reports of schizophrenic patients treated with CBD and a preliminary report of a controlled clinical trial comparing CBD with an atypical antipsychotic drug have confirmed that this cannabinoid can be a safe and well-tolerated alternative treatment for schizophrenia. Future studies of CBD in other psychotic conditions such as bipolar disorder and comparative studies of its antipsychotic effects with those produced by clozapine in schizophrenic patients are clearly indicated.”

“In conclusion, results from pre-clinical and clinical studies suggest that CBD is an effective, safe and well-tolerated alternative treatment for schizophrenic patients. Future trials of this cannabinoid in other psychotic conditions such as bipolar disorder (50) and comparative studies of its antipsychotic effects with those produced by clozapine in schizophrenic patients are clearly needed.”

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000400001&lng=en&nrm=iso&tlng=en

Opposite Effects of Δ-9-Tetrahydrocannabinol and Cannabidiol on Human Brain Function and Psychopathology

 “Pretreatment with CBD prevented the acute induction of psychotic symptoms by Δ-9-tetrahydrocannabinol. Δ-9-THC and CBD can have opposite effects on regional brain function, which may underlie their different symptomatic and behavioral effects, and CBD’s ability to block the psychotogenic effects of Δ-9-THC”

“In healthy individuals, Δ-9-tetrahydrocannabinol (Δ-9-THC), the main psychoactive ingredient of the Cannabis sativa plant, can induce psychotic symptoms and anxiety, and can impair memory and psychomotor control. In patients with schizophrenia, Δ-9-THC may exacerbate existing psychotic symptoms, anxiety and memory impairments, and Δ-9-THC is thought to be the ingredient responsible for the increased risk of developing schizophrenia following regular cannabis use. In contrast, Cannabidiol (CBD), the other major psychoactive constituent of C. sativa, has anxiolytic and possibly antipsychotic properties, does not impair memory or other cognitive functions. Although CBD has been shown to have neuroprotective effects, Δ-9-THC may have neurotoxic as well as neuroprotective effects. Moreover, when co-administered with Δ-9-THC, CBD may be able to reduce some of the symptomatic effects of Δ-9-THC like anxiety and paranoia. CBD may thus have therapeutic potential as a treatment for cannabis-induced psychopathology, and as an anxiolytic and an antipsychotic.”

 “Our data are consistent with a potential therapeutic role for CBD in ameliorating the psychiatric consequences of cannabis use in the general population, and in patients with existing psychiatric disorders, particularly as conventional antipsychotic medication is relatively ineffective for such conditions. It might also have a role in the treatment of psychotic and anxiety disorders independent of cannabis use. From a public health point of view, one worrying implication of our results is that cannabis users may be at an increased risk of acute adverse psychological reactions following cannabis use, in light of the increasingly potent forms of cannabis with decreasing CBD content available on the street.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3055598/

Cannabis as an adjunct to or substitute for opiates in the treatment of chronic pain.

Abstract

“There is a growing body of evidence to support the use of medical cannabis as an adjunct to or substitute for prescription opiates in the treatment of chronic pain. When used in conjunction with opiates, cannabinoids lead to a greater cumulative relief of pain, resulting in a reduction in the use of opiates (and associated side-effects) by patients in a clinical setting. Additionally, cannabinoids can prevent the development of tolerance to and withdrawal from opiates, and can even rekindle opiate analgesia after a prior dosage has become ineffective. Novel research suggests that cannabis may be useful in the treatment of problematic substance use. These findings suggest that increasing safe access to medical cannabis may reduce the personal and social harms associated with addiction, particularly in relation to the growing problematic use of pharmaceutical opiates. Despite a lack of regulatory oversight by federal governments in North America, community-based medical cannabis dispensaries have proven successful at supplying patients with a safe source of cannabis within an environment conducive to healing, and may be reducing the problematic use of pharmaceutical opiates and other potentially harmful substances in their communities.”

http://www.ncbi.nlm.nih.gov/pubmed/22880540

Cannabidiol for the treatment of cannabis withdrawal syndrome: a case report.

Abstract

“What is known and Objective:  Cannabis withdrawal in heavy users is commonly followed by increased anxiety, insomnia, loss of appetite, migraine, irritability, restlessness and other physical and psychological signs. Tolerance to cannabis and cannabis withdrawal symptoms are believed to be the result of the desensitization of CB(1) receptors by THC. Case summary:  This report describes the case of a 19-year-old woman with cannabis withdrawal syndrome treated with cannabidiol (CBD) for 10 days. Daily symptom assessments demonstrated the absence of significant withdrawal, anxiety and dissociative symptoms during the treatment. What is new and Conclusion:  CBD can be effective for the treatment of cannabis withdrawal syndrome.”

http://www.ncbi.nlm.nih.gov/pubmed/23095052

The endocannabinoid system as a target for the treatment of cannabis dependence

“Cannabinoid replacement therapy and CB1 receptor antagonism are two potential treatments for cannabis dependence that are currently under investigation. However, abuse liability and adverse side effects may limit the scope of each of these approaches. A potential alternative stems from the recognition that (i) frequent cannabis use may cause an adaptive downregulation of brain endocannabinoid signaling, and (ii) that genetic traits that favor hyperactivity of the endocannabinoid system in humans may decrease susceptibility to cannabis dependence. These findings suggest in turn that pharmacological agents that elevate brain levels of the endocannabinoid neurotransmitters, anandamide and 2-arachidonoylglycerol (2-AG), might alleviate cannabis withdrawal and dependence. One such agent, the fatty-acid amide hydrolase (FAAH) inhibitor URB597, selectively increases anandamide levels in the brain of rodents and primates. Preclinical studies show that URB597 produces analgesic, anxiolytic-like and antidepressant-like effects in rodents, which are not accompanied by overt signs of abuse liability. In this article, we review evidence suggesting that (i) cannabis influences brain endocannabinoid signaling; and (ii) FAAH inhibitors such as URB597 might offer a possible therapeutic avenue for the treatment of cannabis withdrawal.”

“Direct modulation of CB1receptors as a treatment for cannabis dependence”

“Even though, as we have seen above, direct activation of CB1 receptors may yield variable behavioral responses, low-dosage oral Δ9-THC has shown promise in the management of human cannabis withdrawal. The rationale for this approach is that controlled replacement of Δ9-THC for smoked cannabis may reduce the severity of withdrawal symptoms and allow a dependent individual to remain abstinent. Additionally, given that dependent subjects are experienced with cannabis, and Δ9-THC is administered at low doses, administration of the latter is unlikely to result in the anxiety responses observed with inexperienced users or high dosages. Consistent with this idea, two independent clinical studies have shown that low-dose oral Δ9-THC attenuates withdrawal symptom scores and is minimally intoxicating in non-treatment seeking daily cannabis users.””

“Several therapeutic modalities are currently being considered to treat cannabis dependence, including activation or deactivation of CB1receptors. While these stategies show promise in measures of cannabis withdrawal and abstinence, they may also create problems of abuse liability or adverse emotional effects. An additional approach might be to enhance endogenous anandamide signaling using agents that attenuate the deactivation of this endocannabinoid transmitter.”

“Increasing anandamide signaling with deactivation inhibitors, such as the FAAH blocker URB597, potentiates stress coping behaviors in animals, indicating a role for anandamide in physiopathological context of stress-related responses. Similarly, elevation of anandamide in specific brain regions opposes the anhedonic effects of stress and promotes normal positive responses to pleasurable stimuli in rodents. It is reasonable to hypothesize that these effects could act to blunt the negative affect and stress, which is common during cannabis withdrawal, thus allowing cannabis dependent individuals to successfully abstain from drug use.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2647947/

The endogenous cannabinoid system and the treatment of marijuana dependence.

Abstract

“The active principle of marijuana, Delta9-tetrahydrocannabinol (Delta9-THC), exerts its pharmacological effects by binding to selective receptors present on the membranes of neurons and other cells. These cannabinoid receptors are normally engaged by a family of lipid mediators, called endocannabinoids, which are thought to participate in the regulation of a diversity of brain functions, including pain, mood, appetite and memory. Marijuana use may lead to adaptive changes in endocannabinoid signaling, and these changes might contribute to effects of marijuana as well as to the establishment of marijuana dependence. In the present article, I outline current views on how endocannabinoid substances are produced, released, and deactivated in the brain. In addition, I review recent progress on the development of pharmacological agents that interfere with endocannabinoid deactivation and discuss their potential utility in the treatment of marijuana dependence and other aspects of drug abuse.”

http://www.ncbi.nlm.nih.gov/pubmed/15464150

Endometriosis: Marijuana Treatment

“Dr. Phillip Leveque has spent his life as a Combat Infantryman, Physician, Toxicologist and Pharmacologist.

(MOLALLA, Ore.) – I don’t think I have to explain what this is to anybody. If you have it, you know it. Endometriosis is graded in stages I,II, III & IV, with stage I being “minimized” inconvenience while stage IV is severe and usually requires surgery.

As a physician, I had known about endometriosis for years and that some women become narcotic addicts because of it. Pre Menstrual Tension (PMS) may be concurrent though different and I had many PMS patients as well. Some of them became addicts also. I was not surprised when lady patients came to our clinics offering chart notes that they had been prescribed every conceivable analgesic and other medications but they also told me marijuana works better than any regular prescription.

I have a severe pain problem myself caused by too high of a concentration of spinal anesthesia. I got disgusted by the anesthesiologist telling me he didn’t cause it but I got a new understanding for patients in pain.

If the patient says marijuana works for pain, I believe them. Actually in Oregon about sixty percent of patients have some chronic pain syndrome of nerve, muscle, joint, bone, intestinal or genitourinary. It doesn’t seem to matter whatever the source of pain, the bottom line is that MJ gives relief.

I presume stage I endometriosis and minor PMS are effectively treated with aspirin-like drugs, but when the pain etc. is in the moderate/severe level, the ladies have found out by themselves that marijuana/cannabis is effective without the hazard of narcotic addiction or alcoholism.

The U.S. government publicizes that as many as 77 million Americans have used marijuana and perhaps ten million use it frequently.

Marijuana as folk medicine has been used in the U.S. since the middle 1800’s and probably in Mexico and Latin America since the Spanish introduced it in the late 1500’s.

It is no longer amazing to me when a patient tells me of some new disease for which they have discovered marijuana treatment is beneficial.

It is time the DEA and its hoodlums backed off and allow the therapeutic use of medical marijuana, as more and more people are reverting to this tried and true “folk medicine” everyday.”

http://www.salem-news.com/articles/january032008/endo_med_1308.php

Marijuana Compound Effective In Treating Tourette’s Syndrome, Study Says

“Thursday, 15 May 2003

Hanover, Germany: A primary compound in marijuana, delta-9-tetrahydrocannabinol (THC), is effective in reducing “tics” in patients suffering from Tourette’s Syndrome (TS), according to clinical trail data published in a recent edition of the Journal of Clinical Psychiatry. Tourette’s Syndrome is a complex neuropsychiatric disorder characterized by motor tics (sudden spasms especially in the facial muscles, neck and shoulders) and one or more vocal tics.

Twenty-four patients participated in the double-blind placebo-controlled trial over a period of six weeks. Treatment with up to 10 mg of THC resulted in significant improvement of tic severity, authors wrote. No serious adverse effects to the treatment were reported.

In a separate article published in Neuropsychopharmacology, authors elaborated, “No detrimental effect was seen on learning curve, interference, recall and recognition of word lists, immediate visual memory span, and divided attention” from THC during or after the treatment.

The 24-patient study confirmed previous smaller patient trials that also found THC to be effective in the treatment of tics and behavioral problems in patients with Tourette’s Syndrome.”

http://norml.org/news/2003/05/15/marijuana-compound-effective-in-treating-tourette-s-syndrome-study-says

Marijuana Successfully Treats Tourette’s Syndrome, Study Shows

“Thursday, 11 March 1999

German researchers report that the consumption of the marijuana compound THC alleviates symptoms of Tourette’s Syndrome. The researchers published their findings in this month’s issue of the American Journal of Psychiatry.

“Earlier reports suggested beneficial effects in Tourette’s syndrome when smoking marijuana,” the German research team wrote. “We report a successful treatment of Tourette’s syndrome with delta-9-tetrahydocannabinol, the major psychoactive ingredient of marijuana.”

Tourette’s syndrome is a complex neuropsychiatric disorder that is characterized by sudden spasms, so called “tics,” that occur especially in the face, neck, and shoulders.

The researchers found that a 25-year-old patient treated with 10 mg of THC experienced marked improvement of both vocal and motor tics associated with behavioral disorders. “The improvement began 30 minutes after treatment and lasted for about seven hours,” the researchers reported. “No adverse effects occurred.”

Researchers stated, “This is the first report of a successful treatment of Tourette’s syndrome with delta-9-THC.” They said they are planning to confirm their preliminary results in an upcoming double-blind, placebo controlled, crossover study.

NORML board member Dr. Lester Grinspoon of Harvard Medical School called inhaled marijuana’s effects on patients suffering from Tourette’s “impressive,” and said that the drug holds tremendous potential as a course of treatment for the disease.

For more information, please contact either Allen St. Pierre of The NORML Foundation @ (202) 483-8751 or NORML board member Dr. Lester Grinspoon of Harvard Medical School @ (617) 277-3621.”

http://norml.org/news/1999/03/11/marijuana-successfully-treats-tourette-s-syndrome-study-shows