A possible new treatment approach to obsessive-compulsive disorder

EPD1504: a novel μ-opioid receptor partial agonist attenuates obsessive-compulsive disorder (OCD)-like behaviors

Low doses of μ-opioid receptor (MOR) agonists rapidly ameliorate symptoms in treatment-resistant obsessive-compulsive disorder (OCD) patients (10-50% of OCD patients). However, the utility of MOR agonists is limited by their safety liabilities. We developed a novel MOR partial agonist (EPD1540) that has an improved respiratory safety profile when compared to buprenorphine. Buprenorphine is a MOR partial agonist primarily used in the treatment of opiate-use disorder, which in investigator-led trials, has been shown to rapidly ameliorate symptoms in treatment-resistant OCD patients. In this study, we show that doses of EPD1504 and buprenorphine that occupy small fractions of MORs in the CNS (approximately 20%) are as effective as fluoxetine at ameliorating OCD-like behaviors in two different rat models (an operant probabilistic reversal task and marble burying). Importantly, effective doses of EPD1504 did not impair either locomotor activity, or respiration under normoxic or hypercapnic conditions. Additionally, EPD1504 had effects comparable to buprenorphine in the conditioned place preference assay. These results indicate that EPD1504 may provide a safer alternative to buprenorphine for the treatment of OCD patients.

Treatment-resistant OCD: Pharmacotherapies in adults

Serotonin reuptake inhibitor (SRI) medications are well established as first-line pharmacotherapeutic treatment for Obsessive-Compulsive Disorder (OCD). However, despite the excellent safety profile and demonstrated efficacy of these medications, a substantial proportion of individuals with OCD fail to attain sufficient benefit from SRIs. In this narrative review, we discuss clinical features of OCD that have been associated with poorer response to SRIs, and we present pharmacotherapeutic interventions that have been explored as augmenting or alternative treatments for treatment-resistant OCD. We additionally highlight non-SRI interventions for OCD that are currently under investigation. Pharmacotherapeutic interventions were identified via expert consensus. To assess the evidence base for individual pharmacotherapies, targeted searches for relevant English-language publications were performed on standard biomedical research databases, including MEDLINE. Information relevant to ongoing registered clinical trials in OCD was obtained by search of ClinicalTrials.gov. Pharmacotherapies are grouped for review in accordance with the general principles of Neuroscience-based Nomenclature (NbN). Clinical features of OCD that may suggest poorer response to SRI treatment include early age of onset, severity of illness, duration of untreated illness, and the presence of symmetry/ordering or hoarding-related symptoms. Based on evolving pathophysiologic models of OCD, diverse agents engaging serotonin, dopamine, norepinephrine, glutamate, and anti-inflammatory pathways have been explored as alternative or adjunctive therapies for treatment-resistant OCD and have at least preliminary evidence of efficacy. Medications with dopamine antagonist activity remain the most robustly evidence-based of augmenting interventions, yet dopamine antagonists benefit only a minority of those who try them and carry elevated risks of adverse effects. Interventions targeting glutamatergic and anti-inflammatory pathways are less well evidenced, but may offer more favorable benefit to risk profiles. Ongoing research should explore whether specific interventions may benefit individuals with particular features of treatment-resistant OCD.

Use of Selective Alternative Therapies for Treatment of OCD

About 40% of the people with the obsessive-compulsive-disorder do not experience the desired outcome after the existing treatment, and its several side effects were reported. This systematic review was conducted to evaluate the efficacy and tolerability of alternative drugs and assess the possibility of their use as treatment options for obsessive-compulsive-disorder. The Scientific databases PubMed, Science Direct, Google Scholar, Cochrane, Directory of Open Access Journals, MedRxiv and BioRxiv, were searched from inception to March 2022, using appropriate search strategies for each drug and following the Prisma guidelines 2020. Studies were selected according to the already set criteria and assessed for bias. Data were extracted, and descriptive and continuous data were analyzed and presented as frequency/percentage and mean. A total of 16 observational and interventional studies were included for data extraction. The studies focused on four drugs, Psilocybin (n=4), Cannabis (n=7), Nicotine (n=3), and Morphine (n=2), that were used to test out their effect on OCD symptoms. Overall, the majority of the studies showed promising results by documenting a reduction in Y-BOCS scores. However, few subjects, specifically those using nicotine or Cannabis, did not affect their condition or self-reported worsening symptoms. Few side effects were also noticed. This systematic review found that the drugs mostly showed a positive response. All Psilocybin and morphine users, 88.2% and 74.1% of the nicotine and Cannabis users, respectively, reported experiencing the positive effect of these drugs, indicating that these drugs have the potential to be used in the management of OCD. However, further research is required in this arena to thoroughly understand the mechanism of action by which these drugs produce their therapeutic effect. Policies to destigmatize and encourage clinical trials with these drugs are crucial for exploring the use of these drugs as a treatment option for OCD.

Specialty knowledge and competency standards for pharmacotherapy for adult obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) affects approximately one person in 40 and causes substantial suffering. Evidence-based treatments can benefit many; however, optimal treatment can be difficult to access. Diagnosis is frequently delayed, and pharmacological and psychotherapeutic interventions often fail to follow evidence-based guidelines. To ameliorate this distressing situation, the International OCD Accreditation Task Force of the Canadian Institute for Obsessive-Compulsive Disorders has developed knowledge and competency standards for specialized treatments for OCD through the lifespan. These are foundational to evidence-based practice and will form the basis for upcoming ATF development of certification/accreditation programs. Here, we present specialty standards for the pharmacological treatment of adult OCD. We emphasize the importance of integrating pharmacotherapy with clear diagnosis, appreciation of complicating factors, and evidence-based cognitive behavioral therapy. Clear evidence exists to inform first- and second-line pharmacological treatments. In disease refractory to these initial efforts, multiple strategies have been investigated, but the evidence is more equivocal. These standards summarize this limited evidence to give the specialist practitioner a solid basis on which to make difficult decisions in complex cases. It is hoped that further research will lead to development of a clear, multi-step treatment algorithm to support each step in clinical decision-making.

Psychopharmacological Treatment of Obsessive-Compulsive Disorder (OCD)

Background:

Obsessive-compulsive disorder (OCD) is associated with affective and cognitive symptoms causing personal distress and reduced global functioning. These have considerable societal costs due to healthcare service utilization.

Objective:

Our aim was to assess the efficacy of pharmacological interventions in OCD and clinical guidelines, providing a comprehensive overview of this field.

Methods:

We searched the PubMed database for papers dealing with drug treatment of OCD, with a specific focus on clinical guidelines, treatments with antidepressants, antipsychotics, mood stabilizers, off-label medications, and pharmacogenomics.

Results:

Prolonged administration of selective serotonin reuptake inhibitors (SSRIs) is most effective. Better results can be obtained with a SSRI combined with cognitive behavioral therapy (CBT) or the similarly oriented exposure and response prevention (ERP). Refractory OCD could be treated with different strategies, including a switch to another SSRI or clomipramine, or augmentation with an atypical antipsychotic. The addition of medications other than antipsychotics or intravenous antidepressant administration needs further investigation, as the evidence is inconsistent. Pharmacogenomics and personalization of therapy could reduce treatment resistance.

Conclusions:

SSRI/clomipramine in combination with CBT/ERP is associated with the optimal response compared to each treatment alone or to other treatments. New strategies for refractory OCD are needed. The role of pharmacogenomics could become preponderant in the coming years.

Buprenorphine augmentation improved symptoms of OCD, compared to placebo - Results from a randomized, double-blind and placebo-controlled clinical trial

BACKGROUND

In the search for new psychopharmacologic options in the treatment of obsessive-compulsive disorders (OCD), some findings suggested that augmentation with buprenorphine, a partial-opioid agonist used to treat opioid addiction, moderate acute pain and moderate chronic pain, is worthy of consideration. Accordingly, to explore this possibility further, a double-blinded, placebo-controlled clinical trial was performed.

METHOD

A total of 43 patients (mean age: 34.41 years; SD = 6.58; 53.5% males) with refractory OCD and treated with SSRIs or clomipramine at therapeutic dosages were randomly assigned either to an adjuvant buprenorphine or to an adjuvant placebo condition. Patients completed the Yale-Brown-Obsessive-Compulsive Scale (Y-BOCS) at baseline, weeks 3, 9 and 12 (study completion). Buprenorphine (2-4 mg; sublingual) and placebo (tablets with identical shape, color, consistency, and scent) were given daily.

RESULTS

Symptoms of obsessive-compulsive disorders decreased over time, but more so in the buprenorphine than in the placebo condition. Substantial improvements were observed up to week 3 and then 9. Response and partial response were observed in the buprenorphine at week 9 more than in the placebo condition. The advantage had disappeared by week 12.

CONCLUSIONS

The pattern of results suggests that adjuvant buprenorphine augmentation can reduce symptoms of obsessive-compulsive disorders after only three weeks, compared to a placebo. Adjuvant buprenorphine seems to accelerate symptom improvement.

Promising Treatments for Obsessive-Compulsive Disorder: A Call for Additional Research

Many patients with OCD respond partially or not at all to standard medications and cognitive behavioral therapy approaches, making alternate treatments necessary. We review the preliminary evidence that exists in support of the use of stimulants, high-dose caffeine, opiates, memantine, ondansetron, ketamine, and transcranial magnetic stimulation in some patients with OCD. Although limited by small or modest sample sizes, open-label study designs, and brief follow-up periods, studies suggest that each of these strategies can help some patients who have inadequately responded to first-line treatments. The existing data and the unmet needs of OCD patients justify research attention to further test these treatments' safety and efficacy. Previously untested drugs also deserve attention, especially as recent research has suggested new possible contributors to OCD pathophysiology. Similarly, psychotherapeutic interventions beyond CBT should be investigated, and treatments with preliminary evidence in OCD, including Acceptance Commitment Therapy, Danger Ideation Reduction Therapy, and technology-enabled interventions like computerized CBT and Virtual Reality Exposure Therapy, should be carefully tested.

Buprenorphine augmentation in the treatment of refractory obsessive-compulsive disorder

BACKGROUND

OCD is often refractory to treatment. There is a need for the development of new, non-invasive treatments for severe OCD.

RATIONALE

There is evidence that opiates can be a useful adjunctive treatment in OCD. We summarise our experience with sublingual buprenorphine augmentation of standard pharmacological management of severe OCD.

METHODS

Patients were recruited from a standard psychiatric outpatient clinic and gave their consent to the treatment trial. The severity of the OCD was rated with the Y-BOCS. The buprenorphine was introduced to their existing medication regime at a low dose and the dose increased according to response. In order to gauge the reproducibility of the response the buprenorphine was withdrawn and then reintroduced once symptoms had returned.

RESULTS

4 out of 7 patients with treatment resistant OCD showed a 30% reduction in the Y-BOCS score following buprenorphine augmentation. 3 of the responders were comorbid for other Axis 1 diagnoses. All of the responders had shown some improvement with SSRIs or clomipramine. Non-responders had not shown any improvement with either antidepressant or antipsychotic drugs. Typically improvement appeared within 2 days of initiating buprenorphine and waned within 1 to 2 days of its discontinuation. The dose of buprenorphine required varied between 400 µg and 600 µg a day. One responder managed on alternate day dosing. Reintroduction of buprenorphine resulted in symptom control within 2 to 3 days. The buprenorphine treatment was not associated with significant side-effects and the improvement was maintained without progressive dose escalation.

CONCLUSIONS

Buprenorphine augmentation of standard treatment for OCD can result in clinically meaningful improvement in a proportion of refractory OCD cases. Further treatment trials are indicated.

Differential effects of acute morphine, and chronic morphine-withdrawal on obsessive-compulsive behavior: inhibitory influence of CRF receptor antagonists on chronic morphine-withdrawal

Recent studies have provided convincing evidences for co-morbidity between opioid addiction and obsessive-compulsive disorder (OCD), and the involvement of the corticotrophin-releasing factor (CRF) in the effects of morphine-withdrawal. Some scanty evidences also point towards the role of CRF in OCD and related disorders. But, no evidence indicated the role of CRF in morphine withdrawal associated obsessive-compulsive behavior (OCB). Therefore, the present study investigated the role of CRF in morphine-withdrawal induced OCB in mice. Marble-burying behavior in mice was used to assess OCB as this model has good predictive and face validity. The results revealed that acute morphine dose dependently attenuated the marble burying behavior, whereas withdrawal of chronic morphine was associated with significant rise in marble burying behavior. This indicates the differential effect of acute morphine and chronic morphine-withdrawal on OCB. Further, acute treatment with CRF receptor antagonists like antalarmin (2 and 4 μg/mouse, i.c.v.) or astressin-2B (3 and 10 nmol/mouse, i.c.v.) dose dependently attenuated the peak morphine-withdrawal induced increase in marble burying behavior. Moreover, concomitant treatment with antalarmin (4 μg/mouse, i.c.v.) or astressin-2B (10 nmol/mouse, i.c.v.) along with morphine blocked the morphine-withdrawal associated exacerbation of OCB. These results indicate that OCB associated with morphine withdrawal state is partly mediated by the activation of central CRF receptors.

Opioids and anxiety

The opioid system plays a crucial role in the neural modulation of anxiety. The involvement of opioid ligands and receptors in physiological and dysfunctional forms of anxiety is supported by findings from a wide range of preclinical and clinical studies, including clinical trials, experimental research, and neuroimaging, genetic, and epidemiological data. In this review we provide a summary of studies from a variety of research disciplines to elucidate the role of the opioid system in the neurobiology of anxiety. First, we report data from preclinical studies using animal models to examine the modulatory role of central opioid system on defensive responses conducive to fear and anxiety. Second, we summarize the human literature providing evidence that clinical and experimental human studies are consistent with preclinical models. The implication of these data is that activation of the opioid system leads to anxiolytic responses both in healthy subjects and in patients suffering from anxiety disorders. The role of opioids in suppressing anxiety may serve as an adaptive mechanism, collocated in the general framework of opioid neurotransmission blunting acute negative and distressing affective responses.

Naltrexone augmentation in OCD: a double-blind placebo-controlled cross-over study

Current treatments for Obsessive Compulsive Disorder (OCD) rely primarily on serotonergic mechanisms. However, approximately 30% of patients do not respond to serotonin reuptake inhibitors and remain chronically ill. Given the behavioral similarities between some of the compulsive behaviors in OCD and addiction, we hypothesized that the opioid antagonist naltrexone might attenuate compulsions in OCD as well. The effect of naltrexone augmentation to SRI was compared to placebo in 10 OCD outpatients who had not responded to an adequate dose of SSRI or clomipramine for at least 2 months. Participants underwent 5 weeks of treatment with naltrexone or placebo (and 1 week of tapering) in a randomized, double-blind, cross-over design. Patients were evaluated weekly using the Y-BOCS, CGI, HAM-A, and MADRS scales. A two-way repeated measures MANOVA revealed no significant effect for Y-BOCS. However, while receiving naltrexone, patients had significantly higher scores on CGI, MADRS and HAM-A as compared to placebo. The lack of significant findings on OC symptoms could be due to either ceiling effect or alternatively, due to a non-specific exacerbation on anxiety and depression but not on OC symptoms.

Role of atypical opiates in OCD. Experimental approach through the study of 5-HT(2A/C) receptor-mediated behavior

RATIONALE

The selective serotonin (5-HT) reuptake inhibitors (SSRIs) represent the first-line pharmacotherapy for obsessive-compulsive disorder (OCD), and atypical antipsychotic drugs, which block 5-HT2A receptors, are used in augmentation strategies. Opiate drugs are also effective in treatment-refractory OCD and Tourette syndrome. The 5-HT2A-related behavior (i.e., head twitch) has been related with tics, stereotypes, and compulsive symptoms observed in Tourette syndrome and OCD.

OBJECTIVES

The aim of this study was to explore whether 5-HT2A-related behavior is affected by atypical opiate drugs.

MATERIALS AND METHODS

Head-twitch response was induced in mice by administration of either 5-hydroxytryptophan (5-HTP) or the 5-HT2A/C agonist (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI). Dose-effect curves of atypical opiate drugs [(+/-)-tramadol, (-)-methadone and levorphanol], morphine, and other psychoactive drugs (fluvoxamine, desipramine, nefazodone, and clozapine) were performed. Opioid mechanisms were investigated by administration of naloxone.

RESULTS

All the opiates tested reduced both 5-HTP and DOI-induced behavior in a naloxone-reversible fashion, atypical opiates being more effective. The effects of the other drugs depended on the protocol, clozapine being the most effective.

CONCLUSIONS

Combined 5-HT and opioid properties result in a greater efficacy in antagonizing 5-HT2A-related behavior. These results provide behavioral evidence to support convergent effects of the 5-HT and opioid systems in discrete brain areas, offering the potential for therapeutic advances in the management of refractory stereotypes and compulsive behaviors.

Worsening of obsessive-compulsive symptoms under methadone tapering

There is data supporting the hypothesis that the endogenous opioid system may play a role in the pathophysiology of Obsessive Compulsive Disorder (OCD). The authors report a case of worsening of OCD during methadone tapering, which seems to confirm the role of the opioid system in the pathophysiology of OCD. The possible involvement of the cortico-limbic-basal-ganglia-thalamic circuit in the observed phenomenon is discussed.

Substance use disorders in individuals with body dysmorphic disorder

BACKGROUND

Little is known about substance use disorders (SUDs) in individuals with body dysmorphic disorder (BDD). Although studies have examined SUD comorbidity in BDD, no previous studies have examined clinical correlates of SUD comorbidity.

METHOD

We examined rates and clinical correlates of comorbid SUDs in 176 consecutive subjects with DSM-IV BDD (71% female; mean +/- SD age = 32.5 +/- 12.3 years). Comorbidity data were obtained with the Structured Clinical Interview for DSM-IV. BDD severity was assessed with the Yale-Brown Obsessive Compulsive Scale Modified for BDD, and delusionality (insight) was assessed with the Brown Assessment of Beliefs Scale. Quality of life and social/occupational functioning were examined using the Social Adjustment Scale, Quality of Life Enjoyment and Satisfaction Questionnaire, Medical Outcomes Study 36-Item Short-Form Health Survey, and Range of Impaired Functioning Tool. All variables were compared in BDD subjects with and without lifetime and current SUDs. Data were collected from January 2001 to June 2003.

RESULTS

48.9% of BDD subjects (N = 86) had a lifetime SUD, 29.5% had lifetime substance abuse, and 35.8% had lifetime substance dependence (most commonly, alcohol dependence [29.0%]). 17% (N = 30) had current substance abuse or dependence (9.1% reported current substance abuse, and 9.7% reported current dependence). 68% of subjects with a lifetime SUD reported that BDD contributed to their SUD. There were far more similarities than differences between subjects with a comorbid SUD and those without an SUD, although those with a lifetime SUD had a significantly higher rate of suicide attempts (p = .004).

CONCLUSION

These preliminary results suggest that SUDs are very common in individuals with BDD. Subjects with and without a comorbid SUD were similar in most domains that were examined.

Mu opioid receptor gene as a candidate for the study of obsessive compulsive disorder with and without tics

Obsessive compulsive disorder (OCD) is a complex psychiatric disease characterized by recurring obsessions or compulsions that cause significant distress to the patient. The etiology of this disorder remains largely unknown, although a genetic component has been suggested. Many candidates genes have been evaluated based on a possible serotoninergic and dopaminergic brain dysfunction. We postulate the micro opioid receptor (MOR) gene as a candidate because some observations support a role of the opioid system in OCD. The opioid antagonist, naloxone, rapidly exacerbates OCD symptoms and the opioid agonist, tramadol, was reported to be effective in the treatment of some patients. We studied two single nucleotide polymorphisms (C17T and A118G) in 51 trios with OCD. Genotyping was analyzed with transmission desequilibrium test (TDT). The allelic variant +17T of the C17T polymorphism had a low frequency (1%) in our population that did not allow for statistic analysis. However, for the allelic variant +G of the A118G polymorphism we were able to performed statistical comparisons. Our results showed a trend toward significance (chi(2) McNemar = 3.6, P = 0.065) for TDT in patients with comorbid tics. It is an interesting finding that should be tested in a larger sample of OCD patients with tics.

Opiate sensitivity test in patients with stereotypic movement disorder and trichotillomania

Preliminary data about the therapeutic effect of opiate receptor manipulation in self-injurious behavior (SIB) suggest that endogenous opioid mechanisms may have a pathophysiological role in that condition and their involvement may be dependent on the severity of the SIB. The aim of this study was to use fentanyl-induced prolactin response as an opiate receptor sensitivity test in patients with stereotypic movement disorder (SMD) manifesting SIB (skin picking). Healthy volunteers and trichotillomanic patients were enrolled as comparison subjects. Individuals with trichotillomania (TTM) manifest repetitive, less serious self-mutilation (hair pulling) and are classified under different DSM-IV category than SMD. Therefore, they were considered as patient controls. Ten healthy subjects received 0.05 mg/70 kg and another 10 were given 0.1 mg/70 kg dose of fentanyl intravenously in the AM hours. Five of them had placebo trials. A dose of 0.05 mg/70 kg fentanyl was administered to patients with SMD (n = 10) and TTM (n = 12). Serial blood sampling was performed for prolactin measurements. Fentanyl elevated plasma prolactin in a dose-dependent manner. Patients with skin picking, but not with hair pulling, showed significantly increased responses. This finding supports the involvement of endogenous opioids in the pathomechanism of serious SIB.

The significance of the concept of obsessive-compulsive spectrum disorder to the treatment of chronic nonmalignant pain

The concept of an obsessive-compulsive spectrum of disorders has become useful. This article reviews what has been learned about these conditions (especially in the last few years), and how this information may be helpful to clinicians and researchers who work with patients with chronic nonmalignant pain.

Biological therapies for obsessive-compulsive disorder

Two treatments have demonstrated efficacy in OCD, exposure and response (ritual) prevention (EX/RP) and pharmacotherapy with serotonin reuptake inhibitors (SRIs). In this article, which is the third in a three-part series, the authors present an overview of the role of biological treatments for OCD. The evidence for the efficacy of the serotonin reuptake inhibitors (clomipramine and the five selective serotonin reuptake inhibitors "SSRIs" fluvoxamine, fluoxetine, paroxetine, sertraline, and citalopram) as monotherapy for OCD is reviewed. The authors also discuss the rationale for choosing among these agents for specific patients. Research on other types of medication monotherapies for OCD is also discussed. The authors then cover strategies for treatment-resistant OCD, including combining EX/RP and SRI medication treatment, combining clomipramine and an SSRI, use of augmenting medications, and use of intravenous clomipramine. Findings concerning the use of other somatic therapies for treatment-resistant OCD, including electroconvulsive therapy, neurosurgery, plasma exchange/IV immunoglobulin/maintenance antibiotics, and transcranial magnetic stimulation, are also reviewed. Finally, the authors discuss what is known about matching treatments to patients with certain specific symptom clusters, how long to continue maintenance medication treatment, and how to terminate treatment.