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Pharmacopsychiatry 2024; 57(03): 101-103
DOI: 10.1055/a-2290-6470
Editorial

Medical Cannabis in Psychiatry

Kirsten R. Müller-Vahl
1   Clinic for Psychiatry, social psychiatry and psychotherapy, Hannover Medical School, Hannover, Germany
,
Georg Juckel
2   Department of Psychiatry Psychotherapy and Preventive Medicine, LWL University Hospital of the Ruhr University Bochum, Bochum, Germany
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Keywords

cannabis - tourette-s disorder - depression

In 1982, the Austrian journalist Behr stated, “The history [of hemp] is an infinitely long set of stairs, the lower floors of which consist of depressingly few established facts and all the more conjecture” [1]. Today, more than 40 years later, this statement is still valid. This is more remarkable, since the first written documents on the medicinal use of cannabis already appeared around 2700 BC in China. From there, cannabis conquered the world and reached many other countries, including India (around 800 BC) and Persia (around 600 BC). In parallel, historical sources provide evidence for the medicinal use of cannabis in Egypt in the 16th century BC. Around 50 AD, cannabis is mentioned for the first time in occidental documents for the treatment of “ear problems”. In early medieval Europe (around 1150 AD), the German abbess Hildegard von Bingen suggested cannabis for the treatment of different pain conditions. In Europe, cannabis as medicine reached its heyday between 1880 and 1900. At that time, various pharmaceutical companies (i. e., Merck, Bourroughs, Wellcome, Parke-Davis, and Eli Lilly) produced cannabis preparations that were used for the treatment of various conditions, including pain (such as migraine and menstrual cramps), whooping cough, asthma, sleeping problems, depression, diarrhea, loss of appetite, itching, uterine bleeding, Graves’ disease, and menopausal fever.

The (temporary) decline of medicinal cannabis was related to the development of standardized chemically produced finished products, the pharmaceutical instability of cannabinoids and related difficulties regarding its standardization, difficulties in the characterization of cannabinoids such as delta-9-tetrahydrocannabinol (THC), and finally, opposing economic interests and political decisions resulting in numerous restrictions with respect to the general use of hemp. This cannabis prohibition still exists, but with respect to medicinal use, in several countries, marked changes were introduced after the identification of the chemical structure and stereochemistry of the major plant cannabinoids cannabidiol (CBD, in 1963) and Δ9-THC (in 1964). The final breakthrough with respect to the modern history of cannabis-based medicine was achieved after the identification of the endocannabinoid system (ECS) in humans, including endogenous ligands (endocannabinoids) and cannabinoid receptors. This resulted in a tremendous increase in both basic and clinical research on cannabinoids [2].

However, until today, the therapeutic spectrum of cannabis and cannabis-based medicines is largely unexplored. Therefore, it is still not possible to finally assess in which indications cannabinoids are indicated. This is also because there is evidence that cannabinoids have an unusually and uniquely wide spectrum of different indications. According to the first comprehensive meta-analysis published by Whiting and colleagues in 2015 [3], a “moderate-quality evidence” for efficacy was found for the treatment of chronic pain and spasticity, while a “low-quality evidence” was reported for nausea and vomiting due to chemotherapy, weight gain in those infected with HIV, sleep disorders, and Tourette syndrome. Three years later, in 2018, the American National Academies of Sciences, Engineering, and Medicine came to a very similar assessment reporting good quality evidence that cannabinoids are effective in the treatment of pain, spasticity in multiple sclerosis, and nausea and vomiting due to chemotherapy, while moderate evidence was found in sleep disorders [4].

In recent years, an increasing number of studies demonstrated the beneficial effects of THC-containing compounds in chronic (neuropathic) pain, which is currently the best-investigated and most established indication for cannabinoids. In many countries, cannabinoids are also well-established in palliative care due to their positive effects on various symptoms, including sleep, appetite, anxiety, mood, weight, pain, and agitation [5] [6] [7] [8]. Up to now, only very few cannabis products have been officially licensed: the pure THC (dronabinol) products Marinol and Syndros (only in the US, for the treatment of chemotherapy-induced emesis and AIDS wasting syndrome), the THC analog Nabilone (Cesamet, Canemes) for chemotherapy-induced emesis, the cannabis extract Nabiximols (Sativex) for spasticity in multiple sclerosis, and the CBD extract Epidiolex (also Epidyolex) for Dravet and Lennox Gastaut syndrome, and tuberous sclerosis complex. Although people often use cannabis as self-medication to treat symptoms caused by psychiatric disorders, the database is still weak. There is general agreement that cannabinoids are safe and, in most cases, well tolerated. Most often, side effects of THC are sedation, dizziness, and drowsiness.

In many countries in recent years, the legal situation changed and cannabinoids, including pure THC, CBD, cannabis extracts, and cannabis flowers, can be prescribed off-label or no-label. In some countries, costs for cannabis-based treatment are recovered by health insurance.

The single contributions focus on various issues in this field. Currently, there is no “last word” in this matter. Cannabinoids in psychiatry and psychotherapy are a prospering approach with chances and risks. Perhaps the hype of cannabis-based medicine, psychedelics, and ketamine also has something to do with the stagnation in the development of psychopharmaceutical agents, while millions of patients are still suffering from their diseases, becoming chronically without valid hope to get better.

This special issue of Pharmacopsychiatry provides a collection of review articles covering the current state of “Medical Cannabis in Psychiatry”.

Müller-Vahl [9] summarizes the current findings and insights in her article. The main result is that profound and valid studies, as well as matured cannabis products, are still missing. The increasing evidence for the treatment of autism spectrum disorder, Tourette syndrome, anxiety disorder, and posttraumatic stress disorder (PTSD) is of interest; however, there are no clear hints of efficacy in large psychiatric diseases such as depression, bipolar, dementia, and addiction.

Dammann et al. [10] critically reviewed cannabis in their article. Interestingly, the literature on CBD is more extensive and covers a lot of aspects. The authors have chosen approximately one-third from around 150 published articles. These reports mainly consist of studies concerning substance abuse, schizophrenia, anxiety, and PTSD. All other diagnoses have either not been investigated or not in a systematic manner. Thus, these authors also request more studies be performed in this field, especially in regard to the long-term stabilizing effects of CBD.

How is the situation concerning the real usage of cannabis in medical care or for medical purposes? Szejko et al. [11] report the results from a German study in their article. Over 1000 users of different cannabis strains participated. They had a prescription from a physician and reported usage for about one year to find relief from pain, gastrointestinal, neurologic, as well as psychiatric symptoms. About 80% of the patients profited from this application. There were no tremendous side effects. Almost 40% of the patients gave the information that their health insurance covers the cost of this treatment. These findings underline the view that cannabis is proceeding in the daily treatment of ill people and a debate of legalization and automatic takeover of the costs for those with a medical indication has to be intensified.

The situation in North America is quite different because cannabis and other “drugs” are often prescribed and their usage is tolerated by the society. Thus, Das et al. [12] present interesting findings and insights in that situation in their article. They have conducted detailed qualitative interviews with psychiatric patients who use cannabis to improve their symptoms. The authors revealed the broad range and complexity of motivations, perceptions, and patterns of taking cannabis in these patients. They stated that the medical doctor-patient interaction in such treatment versus the traditional is important to find the right individual way. This should be more educated.

Karst [13] summarizes the state of the art concerning. He concluded that the endocannabinoid system plays a central role in the regulation of pain independently of its causation. The evidence level of the clinical literature is moderate. It can be recommended for stress-associated pain regulation and sleep improvement in patients with severe and chronic pain disorders.

Finally, Broers and Bianchi [14] explored the current situation of the efficacy of cannabis in old age in their article. Symptoms of dementia are not responding to low-dose oral synthetic THC. However, recent studies using THC/CBD at higher doses interestingly showed promising results and good tolerability. The authors suggest that cannabinoids might also have good effects on the behavioral disorders of demented patients as well as the surrounding social situation.

Medical cannabis, as part of modern psychopharmacology and treatment, is a timely and promising field and could broaden our therapeutic possibilities in severe and chronically ill patients. But more research, especially large clinical trials, is strongly needed besides the desire for wide clinical experience to come to an appropriate final assessment of cannabinoids in psychiatry, including the risk of psychoses, depression, and dependence.


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Conflict of Interest

The authors declare that they have no conflict of interest.


Correspondence

Professor Georg Juckel, MD
Department of Psychiatry Psychotherapy and Preventive Medicine
LWL University Hospital of the Ruhr University Bochum
Alexandrinenstr.1
44791 Bochum
Germany   

Publication History

Received: 23 February 2024
Received: 06 March 2024

Accepted: 07 March 2024

Article published online:
07 May 2024

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