Effect of dronabinol therapy on physical activity in anorexia nervosa: a randomised, controlled trial

Exploring the influence of circulating endocannabinoids and nucleus accumbens functional connectivity on anorexia nervosa severity

Anorexia nervosa (AN) is a severe psychiatric disorder characterized by a harmful persistence of self-imposed starvation resulting in significant weight loss. Research suggests that alterations in the nucleus accumbens (NAcc) and circulating endocannabinoids (eCBs), such as anandamide (AEA) and 2-arachidonoylglycerol (2-AG), may contribute to increased severity and maladaptive behaviors in AN, warranting an examination of the interplay between central reward circuitry and eCBs. For this purpose, we assessed NAcc functional connectivity and circulating AEA and 2-AG concentrations in 18 individuals with AN and 18 healthy controls (HC) to test associations between circulating eCBs, NAcc functional connectivity, and AN severity, as defined by body mass index (BMI). Decreased connectivity was observed between the NAcc and the right insula (NAcc-insula; pFWE < 0.001) and the left supplementary motor area (NAcc-SMA; pFWE < 0.001) in the AN group compared to HC. Reduced NAcc-insula functional connectivity mediated the association between AEA concentrations and BMI in the AN group. However, in HC, NAcc-SMA functional connectivity had a mediating role between AEA concentrations and BMI. Although no significant differences in eCBs concentrations were observed between the groups, our findings provide insights into how the interaction between eCBs and NAcc functional connectivity influences AN severity. Altered NAcc-insula and NAcc-SMA connectivity in AN may impair the integration of interoceptive, somatosensory, and motor planning information related to reward stimuli. Furthermore, the distinct associations between eCBs concentrations and NAcc functional connectivity in AN and HC could have clinical implications for weight maintenance, with eCBs being a potential target for AN treatment.

The relationship between cannabis and anorexia nervosa: a scoping review

BACKGROUND

Relapse rates in Anorexia Nervosa (AN) remain high, warranting exploration of further treatments. Cannabinoid agonists are of interest as they have shown successful outcomes in the treatment of associated conditions, such as post-traumatic stress disorder. This scoping review explores the endocannabinoid system (ECS), benefits/harms/null effects of cannabinoid treatment, and harms of cannabis use in AN.

METHODS

PubMed, PsycINFO, Cochrane, and Web of Science were searched for studies published between 2010 and August 2023, with human participants that explored the ECS, cannabinoid treatment, or cannabis use, and included 1 or more keywords for both cannabis and AN in the title and or abstract. Reports describing secondary anorexia, reports not available in English, grey literature, reports combining data from AN with other conditions, and reports only reporting the prevalence of cannabis abuse/dependence were excluded. Data were extracted from 17 reports (n = 15 studies). For the ECS, outcomes included genetics such as allele expression related to the ECS, cannabinoid receptor availability, and circulating levels of endocannabinoids. For benefits/harms/null effects of cannabinoid treatment, outcomes included changes in weight, eating disorder (ED) symptoms, physical activity (PA), and hormones. For harms of cannabis use, outcomes included genetics related to cannabis use disorder and associations between cannabis use and ED symptoms.

RESULTS

Eight studies (n = 8 reports) found abnormalities in the ECS in AN including expression of related alleles, genotypes, and haplotypes, availability of cannabinoid receptors, and levels of endocannabinoids. Three studies (n = 5 reports) found benefits/harms/null effects of cannabinoid treatment. Benefits included weight gain, improved ED symptoms and reduced PA, while null effects included no changes in weight or ED symptoms, and harms included increased PA and lowered adipose hormones. Four studies (n = 4 reports) expanded upon harms of cannabis use, including genetic predispositions to cannabis use disorder, and compensatory behaviors related to cannabis use.

CONCLUSION

Limited evidence suggests that abnormalities in the ECS in AN may render cannabis a potential treatment for weight restoration and associated symptoms. Future research may wish to investigate individualized dosing approaches to maximize beneficial effects while minimizing harms. Level II Evidence: Scoping Review.

Pharmacotherapy, alternative and adjunctive therapies for eating disorders: findings from a rapid review

BACKGROUND

The current review broadly summarises the evidence base for pharmacotherapies and adjunctive and alternative therapies in the treatment of eating disorders and disordered eating.

METHODS

This paper forms part of a Rapid Review series examining the evidence base in the field of eating disorders. This was conducted to inform the Australian National Eating Disorder Research and Translation Strategy 2021-2030. ScienceDirect, PubMed and Ovid/Medline were searched for included studies published between 2009 and 2021 in English. High-level evidence such as meta-analyses, large population studies and randomised control trials were prioritised, and grey literature excluded. Data from included studies relating to pharmacotherapy, and to adjunctive and alternative therapies in eating disorders, were synthesised and disseminated in the current review.

RESULTS

A total of 121 studies were identified, relating to pharmacotherapy (n = 90), adjunctive therapies (n = 21) and alternative therapies (n = 22). Some of the identified studies involved combinations of the above (e.g. adjunctive pharmacotherapy). Evidence of efficacy of interventions across all three categories was very limited with few relevant high quality clinical trials. There was a particular scarcity of evidence around effective treatments for anorexia nervosa (AN). With treatment of bulimia nervosa (BN), fluoxetine has exhibited some efficacy leading to regulatory approval in some countries. With binge eating disorder (BED), recent evidence supports the use of lisdexamfetamine. Neurostimulation interventions show some emerging efficacy in the treatment of AN, BN and BED but some, such as deep brain stimulation can be highly invasive.

CONCLUSION

Despite widespread use of medications, this Rapid Review has identified a lack of effective medications and adjunctive and alternative therapies in the treatment of EDs. An intensification of high-quality clinical trial activity and drug discovery innovation are required to better assist patients suffering from EDs.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines update 2023 on the pharmacological treatment of eating disorders

OBJECTIVES

This 2023 update of the WFSBP guidelines for the pharmacological treatment of eating disorders (EDs) reflects the latest diagnostic and psychopharmacological progress and the improved WFSBP recommendations for the assessment of the level of evidence (LoE) and the grade of recommendation (GoR).

METHODS

The WFSBP Task Force EDs reviewed the relevant literature and provided a timely grading of the LoE and the GoR.

RESULTS

In anorexia nervosa (AN), only a limited recommendation (LoE: A; GoR: 2) for olanzapine can be given, because the available evidence is restricted to weight gain, and its effect on psychopathology is less clear. In bulimia nervosa (BN), the current literature prompts a recommendation for fluoxetine (LoE: A; GoR: 1) or topiramate (LoE: A; GoR: 1). In binge-eating disorder (BED), lisdexamfetamine (LDX; LoE: A; GoR: 1) or topiramate (LoE: A; GoR: 1) can be recommended. There is only sparse evidence for the drug treatment of avoidant restrictive food intake disorder (ARFID), pica, and rumination disorder (RD).

CONCLUSION

In BN, fluoxetine, and topiramate, and in BED, LDX and topiramate can be recommended. Despite the published evidence, olanzapine and topiramate have not received marketing authorisation for use in EDs from any medicine regulatory agency.

Medical cannabinoids: a pharmacology-based systematic review and meta-analysis for all relevant medical indications

BACKGROUND

Medical cannabinoids differ in their pharmacology and may have different treatment effects. We aimed to conduct a pharmacology-based systematic review (SR) and meta-analyses of medical cannabinoids for efficacy, retention and adverse events.

METHODS

We systematically reviewed (registered at PROSPERO: CRD42021229932) eight databases for randomized controlled trials (RCTs) of dronabinol, nabilone, cannabidiol and nabiximols for chronic pain, spasticity, nausea /vomiting, appetite, ALS, irritable bowel syndrome, MS, Chorea Huntington, epilepsy, dystonia, Parkinsonism, glaucoma, ADHD, anorexia nervosa, anxiety, dementia, depression, schizophrenia, PTSD, sleeping disorders, SUD and Tourette. Main outcomes and measures included patient-relevant/disease-specific outcomes, retention and adverse events. Data were calculated as standardized mean difference (SMD) and ORs with confidence intervals (CI) via random effects. Evidence quality was assessed by the Cochrane Risk of Bias and GRADE tools.

RESULTS

In total, 152 RCTs (12,123 participants) were analysed according to the type of the cannabinoid, outcome and comparator used, resulting in 84 comparisons. Significant therapeutic effects of medical cannabinoids show a large variability in the grade of evidence that depends on the type of cannabinoid. CBD has a significant therapeutic effect for epilepsy (SMD - 0.5[CI - 0.62, - 0.38] high grade) and Parkinsonism (- 0.41[CI - 0.75, - 0.08] moderate grade). There is moderate evidence for dronabinol for chronic pain (- 0.31[CI - 0.46, - 0.15]), appetite (- 0.51[CI - 0.87, - 0.15]) and Tourette (- 1.01[CI - 1.58, - 0.44]) and moderate evidence for nabiximols on chronic pain (- 0.25[- 0.37, - 0.14]), spasticity (- 0.36[CI - 0.54, - 0.19]), sleep (- 0.24[CI - 0.35, - 0.14]) and SUDs (- 0.48[CI - 0.92, - 0.04]). All other significant therapeutic effects have either low, very low, or even no grade of evidence. Cannabinoids produce different adverse events, and there is low to moderate grade of evidence for this conclusion depending on the type of cannabinoid.

CONCLUSIONS

Cannabinoids are effective therapeutics for several medical indications if their specific pharmacological properties are considered. We suggest that future systematic studies in the cannabinoid field should be based upon their specific pharmacology.

Potential therapeutic benefits of cannabinoid products in adult psychiatric disorders: A systematic review and meta-analysis of randomised controlled trials

The utility of cannabinoids and cannabinoid-based products (CBPs) as a pharmacological aid to treat psychiatric disorders in adulthood is still poorly understood despite a number of comprehensive general reviews discussing the topic. With a focus on randomized controlled trial (RCT) data, this review and meta-analysis aimed to aggregate and evaluate all current high-quality (Level-1) research that specifically assessed the effectiveness of a CBP on a diagnosed adult psychiatric disorder. The following databases, from their inception to September 2020, were included in the search: Academic Search Premier, PubMed, Ovid MEDLINE®, Web of Science™, PsycARTICLES, PsycINFO, CINAHL (Nursing and Allied Health), and Scopus. Risk of bias for each study was individually assessed using the revised Cochrane tool. Of the 2397 papers identified, thirty-one RCTs met criteria for inclusion: ten trials focused on treating cannabis use disorder, six on schizophrenia, five on opioid/tobacco use disorder, three on anxiety disorders, two on Tourette's disorder, two on anorexia nervosa, and one trial each for attention-deficit/hyperactivity disorder, posttraumatic stress disorder, and obsessive compulsive disorder. This review finds limited evidence for the effectiveness of CBPs to acutely treat a narrow range of psychiatric symptoms. We report no evidence supporting the mid- to long-range effectiveness of any currently available CBP. In general, quality of the evidence was assessed as low- to moderate. Importantly, none of the studies discussed in this review presently endorse the use of cannabis flower as a method of treatment for any recognized psychiatric disorder. Larger, hypothesis driven RCTs are required prior to making further therapeutic recommendations.

Approved cannabinoids for medical purposes - Comparative systematic review and meta-analysis for sleep and appetite

BACKGROUND

Cannabinoids are used for numerous disease indications. However, cannabinoids can also produce adverse effects; for example, they can disturb physiological functions such as sleep and appetite. The medical use of cannabinoids refers to a wide variety of preparations and products. Approved cannabinoid products include dronabinol ((-)-trans-Δ⁹-tetrahydrocannabinol (THC), nabilone (a THC analogue), and cannabidiol (CBD) that differ in their pharmacology and may thus have different adverse effects on sleep and appetite.

OBJECTIVES

Here we ask if (i) cannabinoids decrease sleep and appetite in somatic patients or patients that suffer from mental illness and if (ii) there is a difference between THC products (nabilone, dronabinol), vs. CBD in disturbing these physiological functions.

METHODS

In order to answer these two questions, we performed a comparative systematic review (SR) for nabilone, dronabinol, and CBD. For the comparative SR we searched PubMed, Medline, Embase, and PsycINFO for randomized controlled trials (RCTs) and extracted information for adverse side effects or outcomes reporting a negative impact on sleep and appetite. RCT evidence was calculated as odds ratios (ORs) via fixed effects meta-analyses. Evidence quality was assessed by the Cochrane Risk of Bias and GRADE tools. This study is registered at PROSPERO (CRD42021229932).

FINDINGS

A total of 17 RCTs (n = 1479) and 15 RCTs (n = 1974) were included for sleep and appetite, respectively. Pharmaceutical THC (nabilone, dronabinol) does not affect sleep or appetite. In contrast, there is moderate evidence that CBD decreases appetite (OR = 2.46 [1.74:4.01] but has also no effect on sleep.

INTERPRETATIONS

Our comparative systematic study shows that approved cannabinoids can decrease appetite as a negative side effect - an effect that seems to be driven by CBD. Approved cannabinoid products do not negatively affect sleep in somatic and psychiatric patients. This article is part of the special Issue on "Cannabinoids".

Treatment studies with cannabinoids in anorexia nervosa: a systematic review

INTRODUCTION

Anorexia nervosa (AN) is a psychiatric disorder with a high mortality and unknown etiology, and effective treatment is lacking. For decades, cannabis has been known to cause physical effects on the human body, including increasing appetite, which may be beneficial in the treatment of AN.

OBJECTIVE

To systematically review the literature for evidence of an effect of cannabinoids on (1) weight gain, and (2) other outcomes, in AN.

METHOD

A systematic review was done using three databases Embase, PubMed and Psychinfo. The review was registered in PROSPERO with ID number CRD42019141293 and was done according to PRISMA guidelines.

RESULTS

There were 1288 studies identified and after thorough review and exclusion of copies, 4 studies met the inclusion criteria. Three studies used the same AN population and utilized data from one original study, leaving only two original studies. Both of these were Randomized Controlled Trials that explored the effects of delta-9-tetrahydrocannabinol (Δ9-THC) or dronabinol in AN, whereof one study was properly designed and powered and showed a weight increase of an added 1 kg over 4 weeks over placebo.

DISCUSSION AND CONCLUSION

There are few studies and the level of evidence is low. The only properly designed, low bias and highly powered study found a weight increasing effect of dronabinol in AN, while the other, using Δ9-THC at a high dose, found no effect and where the dose may have counteracted the weight gaining effects due to adverse events. More research on cannabinoids in anorexia nervosa is warranted, especially its effects on psychopathology.

LEVEL OF EVIDENCE

Level I, systematic review.

Are There Therapeutic Benefits of Cannabinoid Products in Adult Mental Illness?

A position statement developed by the Canadian Psychiatric Association's (CPA) Research Committee and approved by the CPA's Board of Directors on May 13, 2020.

Possible therapeutic applications of cannabis in the neuropsychopharmacology field

Cannabis use induces a plethora of actions on the CNS via its active chemical ingredients, the so-called phytocannabinoids. These compounds have been frequently associated with the intoxicating properties of cannabis preparations. However, not all phytocannabinoids are psychotropic, and, irrespective of whether they are psychotropic or not, they have also shown numerous therapeutic properties. These properties are mostly associated with their ability to modulate the activity of an intercellular communication system, the so-called endocannabinoid system, which is highly active in the CNS and has been found altered in many neurological disorders. Specifically, this includes the neuropsychopharmacology field, with diseases such as schizophrenia and related psychoses, anxiety-related disorders, mood disorders, addiction, sleep disorders, post-traumatic stress disorder, anorexia nervosa and other feeding-related disorders, dementia, epileptic syndromes, as well as autism, fragile X syndrome and other neurodevelopment-related disorders. Here, we gather, from a pharmacological and biochemical standpoint, the recent advances in the study of the therapeutic relevance of the endocannabinoid system in the CNS, with especial emphasis on the neuropsychopharmacology field. We also illustrate the efforts that are currently being made to investigate at the clinical level the potential therapeutic benefits derived from elevating or inhibiting endocannabinoid signaling in animal models of neuropsychiatric disorders.

Targeting the Endocannabinoid CB1 Receptor to Treat Body Weight Disorders: A Preclinical and Clinical Review of the Therapeutic Potential of Past and Present CB1 Drugs

Obesity rates are increasing worldwide and there is a need for novel therapeutic treatment options. The endocannabinoid system has been linked to homeostatic processes, including metabolism, food intake, and the regulation of body weight. Rimonabant, an inverse agonist for the cannabinoid CB1 receptor, was effective at producing weight loss in obese subjects. However, due to adverse psychiatric side effects, rimonabant was removed from the market. More recently, we reported an inverse relationship between cannabis use and BMI, which has now been duplicated by several groups. As those results may appear contradictory, we review here preclinical and clinical studies that have studied the impact on body weight of various cannabinoid CB1 drugs. Notably, we will review the impact of CB1 inverse agonists, agonists, partial agonists, and neutral antagonists. Those findings clearly point out the cannabinoid CB1 as a potential effective target for the treatment of obesity. Recent preclinical studies suggest that ligands targeting the CB1 may retain the therapeutic potential of rimonabant without the negative side effect profile. Such approaches should be tested in clinical trials for validation.

How effective and safe is medical cannabis as a treatment of mental disorders? A systematic review

We conducted a review of systematic reviews (SRs) and randomized-controlled trials (RCTs) to analyze efficacy and safety of cannabis-based medication in patients with mental disorders. Five data bases were systematically searched (2006-August 2018); 4 SRs (of 11 RCTs) and 14 RCTs (1629 participants) were included. Diagnoses were: dementia, cannabis and opioid dependence, psychoses/schizophrenia, general social anxiety, posttraumatic stress disorder, anorexia nervosa, attention-deficit hyperactivity disorder, and Tourette`s disorder. Outcome variables were too heterogeneous to conduct a  meta-analysis. A narrative synthesis method was applied. The study quality was assessed using the risk-of-bias tool and SIGN-checklists. THC- and CBD-based medicines, given as adjunct to pharmaco- and psychotherapy, were associated with improvements of several symptoms of mental disorders, but not with remission. Side effects occurred, but severe adverse effects were mentioned in single cases only. In order to provide reliable treatment recommendations, more and larger RCTs with follow-up assessments, consistent outcome measures and active comparisons are needed.

MECHANISMS IN ENDOCRINOLOGY: Anorexia nervosa and endocrinology: a clinical update

Anorexia nervosa is a syndrome, that is collections of symptoms, which is not defined by its etiology. The severe cases are intractable. The syndrome is associated with multiple, profound endocrine alterations which may be adaptive, reactive or etiologic. Adaptive changes potentially may be inappropriate in clinical settings such as inpatient intensive re-nutrition or in a setting with somatic comorbidity. Electrolyte levels must be closely monitored during the refeeding process, and the need for weight gain must be balanced against potentially fatal refeeding complications. An important focus of clinical research should be to identify biomarkers associated with different stages of weight loss and re-nutrition combined with psychometric data. Besides well-established peripheral endocrine actions, several hormones also are released directly to different brain areas, where they may exert behavioral and psychogenic actions that could offer therapeutic targets. We need reliable biomarkers for predicting outcome and to ensure safe re-nutrition, however, first of all we need them to explore the metabolism in anorexia nervosa to open new avenues with therapeutic targets. A breakthrough in our understanding and treatment of this whimsical disease remains. Considering this, the aim of the present review is to provide an updated overview of the many endocrine changes in a clinical perspective.

The effect of dronabinol in a male patient with anorexia nervosa suffering from severe acute urge to be physically active

OBJECTIVE

A 27-year-old male suffering from chronic anorexia nervosa was admitted for inpatient psychotherapy suffering from severe urge to be physically active.

METHODS

An off-label treatment with dronabinol was initiated, to reduce his symptoms related to that urge. Several attempts to reduce symptoms including intensive psychotherapy and several psychopharmacological agents had failed in the past.

RESULTS

Following treatment with 7.5 mg dronabinol twice a day, the patient reported a significant reduction in his acute urge to be physically active. Also eating disorder-specific cognitions and compulsive behaviors remitted.

DISCUSSION

Previous studies have applied much lower doses and showed no effect of dronabinol upon the urge to be physically active. Up to date, the patient reported no side effects, especially no psychotropic effects. Implications of this case report are discussed.

Pharmacotherapy of eating disorders

PURPOSE OF REVIEW

Medications are commonly prescribed in the treatment of eating disorders. In this review, we discuss relevant medications used for the treatment of bulimia nervosa, binge eating disorder (BED), and anorexia nervosa. We focus on recent research developments, where applicable, in addition to discussing important findings from older studies to provide a complete synopsis of the current evidence base for eating disorder treatment using pharmacologic agents.

RECENT FINDINGS

Medications are generally useful for patients with bulimia nervosa and BED. For bulimia nervosa, antidepressant medications are the primary pharmacologic treatment and limited new research has been completed. For BED, lisdexamfetamine is reported to be generally well tolerated and effective, and is the first medication to be indicated by the US Food and Drug Administration for treatment of BED. For anorexia nervosa, there is limited evidence supporting benefits of medications. Second-generation antipsychotics, particularly olanzapine, appear to demonstrate some benefit for weight gain in anorexia nervosa, although are not advised as a stand-alone treatment. Transdermal administration of hormonal agents is also being explored for improving bone health in anorexia nervosa.

SUMMARY

Although pharmacotherapy has established utility in bulimia nervosa and BED, further research on medications for the treatment of eating disorders, particularly anorexia nervosa, is necessary.

Changes in IGF-I, urinary free cortisol and adipokines during dronabinol therapy in anorexia nervosa: Results from a randomised, controlled trial

OBJECTIVE

Anorexia nervosa (AN) is characterised by complex neuroendocrine disturbances due to severe underweight, physical hyperactivity and purging behaviour. Cannabinoid agonists are used to palliate cachexia of various causes, but their interactions with the hormonal systems that are involved in energy metabolism have not been previously described in humans. Therefore we found it of interest to assess interactions between the synthetic cannabinoid agonist dronabinol and insulin-like growth factor I (IGF-I), urinary free cortisol (UFC) and adipokines in patients with chronic AN.

DESIGN

This was a prospective, double-blind randomised crossover study, conducted at a specialised care centre for eating disorders. The results are based on twenty-four adult women with chronic AN, who completed the study. The participants received dronabinol (oral capsules, 5mg daily) and matching placebo over four weeks, separated by a four-week washout period. Bioactive IGF was determined by a cell-based bioassay, whereas total IGF-I, IGFBP-2 and -3 and the two adipokines leptin and adiponectines were measured by immunoassays. The UFC excretion was determined by mass spectrometry.

RESULTS

As previously reported, dronabinol treatment caused a small, yet significant increase in BMI as compared to placebo (+0.23 kg/m(2); P = 0.04). This modest weight gain predicted a corresponding increase in bioactive IGF-I, while the amount of daily energy expenditure due to physical activity had a comparable but opposite effect. Nevertheless, neither IGF-I, bioactive IGF nor the IGFBPs levels changed significantly during dronabinol intervention as compared to placebo. Adiponectin also remained unaffected by the weight gain, whereas plasma leptin showed a transient increase at three weeks (P < 0.05). UFC levels were decreased during dronabinol intervention.

CONCLUSION

Our results showed that low-dosage therapy with the synthetic cannabinoid agonist dronabinol affected neither the concentration nor the activity of the circulating IGF-system in women with severe and chronic AN. However, our results suggest that such treatment may alleviate the increased hypothalamic-pituitary-adrenal axis activity seen in these patients.

Psychopharmacologic treatment of eating disorders: emerging findings

Psychopharmacologic treatment is playing a greater role in the management of patients with eating disorders. In this paper, we review randomized, placebo-controlled trials (RCTs) conducted in anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED), and other eating disorders over the past 3 years. Fluoxetine remains the only medication approved for an eating disorder, that being BN. RCTs of antipsychotics in AN have had mixed results; the only agent with some evidence of efficacy is olanzapine. One study suggests dronabinol may induce weight gain in AN. Preliminary studies suggest lack of efficacy of alprazolam, dehydroepiandrosterone, or physiologic estrogen replacement in AN; erythromycin in BN; and the opioid antagonist ALKS-33 in BED. In BED with obesity or overweight, bupropion may cause mild weight loss without seizures, and chromium may improve glucose regulation. Also in BED, three RCTs suggest the stimulant prodrug lisdexamfetamine may reduce binge eating episodes, and another RCT suggests intranasal naloxone may decrease time spent binge eating. There remains a disconnection between the size of eating disorders as a public health problem and the lack of pharmacotherapy research of these conditions.