Combined fluvoxamine and extended-release methylphenidate improved treatment response compared to fluvoxamine alone in patients with treatment-refractory obsessive-compulsive disorder: A randomized double-blind, placebo-controlled study

Clinical Recommendations for Augmentation Agents in Obsessive-Compulsive Disorder Partially Responsive to Serotonin Reuptake Inhibitors

BACKGROUND

Obsessive-compulsive disorder (OCD) affects 2% to 3% of adults worldwide. Although serotonin reuptake inhibitors (SRIs) reliably demonstrate efficacy for this condition, 40% to 60% of patients only achieve partial recovery. The purpose of this systematic review was to assess the efficacy of other agents that may be used as augmentation agents for patients who are partial responders to SRI monotherapy.

METHODS

Using PRISMA-P guidelines, PubMed and Embase were searched using the randomized controlled trial (RCT) filter and the key word "obsessive-compulsive disorder." To be considered for analysis, a potential augmentation agent needed to have at least 2 RCTs. This review specifically analyzes the effect of each augmentation agent on OCD symptoms as measured by the Yale-Brown Obsessive-Compulsive Scale.

RESULTS

The augmentation agents analyzed in this review are d-cycloserine (2 RCTs), memantine (4 RCTs), N-acetylcysteine (5 RCTs), lamotrigine (2 RCTs), topiramate (3 RCTs), riluzole (2 RCTs), ondansetron (2 RCTs), celecoxib (2 RCTs), aripiprazole (5 RCTs), risperidone (7 RCTs), quetiapine (9 RCTs), and olanzapine (3 RCTs).

IMPLICATIONS

The augmentation agents most supported by this review for OCD that is only a partial response to SRI monotherapy are lamotrigine, memantine, and aripiprazole. If an antipsychotic must be used and aripiprazole is not tolerated, risperidone may be considered as an alternative. Unlike the SRI class effect for OCD symptom reduction, augmentation agents demonstrate considerable intraclass variability.

Pharmacological augmentation of serotonin reuptake inhibitors in patients with obsessive-compulsive disorder: A network meta-analysis

OBJECTIVES

The augmentation of serotonin reuptake inhibitors (SRIs) can be achieved by add-on therapy with different pharmacological agents in obsessive-compulsive disorder (OCD) for a better clinical outcome. This network meta-analysis (NMA) was conducted to evaluate and compare the effects of available augmentation agents for SRIs in OCD.

METHOD

The data was extracted from 59 relevant clinical trials after a literature search on MEDLINE/PubMed, Scopus, Cochrane databases and clinical trial registries. PRISMA guidelines were followed in data extraction, analysis and reporting. Random effects Bayesian NMA was done to pool the effects across the interventions for the change in Yale-Brown Obsessive-Compulsive Scale (YBOCS) scoring from baseline to the end of the study. Network graph was built, consistency model was run, node splitting analysis was performed, treatments were ranked as per SUCRA score and meta-regression was done for refractoriness to SRIs and duration of augmentation therapy as the predictor variables.

RESULTS

The drugs showing significant reduction in YBOCS scoring were pregabalin (MD:-8.1;95% CrI: -16, -0.43), memantine (MD:-6.2;95% CrI: -9.9, -2.3), lamotrigine (MD:-6;95% CrI: -12, -0.47), ondansetron (MD:-5.7;95% CrI: -11, -0.67), granisetron (MD:-5.6;95% CrI: -11, -0.44), aripiprazole (MD:-5.4;95% CrI:-9.1, -1.6), risperidone (MD:-3.3;95% CrI: -6.4, -0.20) and topiramate (MD:-5.3;95% CrI: -9.6, -0.97). The node-split analysis showed that direct and indirect pooled effect sizes for all comparisons were comparable. Meta-regression showed a statistically non-significant association between YBOCS score reduction with the duration of augmentation therapy, but significant with SRI-refractory status. Finally, the results were sorted based on certainty of evidence.

CONCLUSION

Memantine was found to be most effective augmentation agent for SRIs in OCD, followed by lamotrigine, ondansetron and granisetron with moderate certainty of evidence. The augmentation agents showed better symptom reduction in patients with SRI-refractory OCD in comparison to non-refractory OCD.

PROSPERO REGISTRATION

CRD42022360110.

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.

Predictors for 12-month long-term outcome in patients with obsessive-compulsive disorder: The influence of duration of untreated illness and age at onset

BACKGROUND

It remains unknown whether the duration of untreated illness (DUI) may play a critical role in clinical improvement of patients with obsessive-compulsive disorder (OCD). Using a relatively large sample of subjects with OCD, this study investigated the potential impact of the DUI on patients' clinical course and long-term treatment response.

METHODS

Two hundred and seven patients with OCD recruited by the OCD outpatient clinic of our university hospital participated in the study. The sample was divided into two groups according to the median DUI (DUI≤3 years and DUI >3 years). Patients were treated with selective serotonin reuptake inhibitors or venlafaxine for 48 weeks in open-label conditions. Treatment response and other clinical variables were analysed.

RESULTS

The total sample showed a mean (SD) DUI of 4.07 (3.5) years, and the mean (SD) illness duration was 6.27 (6.5) years. More than half of the patients had not been treated before (56.5% for OCD). With a median of 3 years as cutoff DUI, response rates were found to be significantly higher in subjects with a short DUI (p < 0.001). Regression analyses showed that a short (≤3 years) DUI and later age at onset predicted better response and higher Y-BOCS scores percentage changes at the endpoint of 48 weeks (β = -1.11, p = 0.003). In addition, there was no correlation between DUI and age of onset in the total patients (r = -0.13, p＞0.05).

CONCLUSIONS

This preliminary study suggests associations between a shorter duration of untreated OCD and favourable long-term outcomes, and a longer DUI with a worse clinical course.

Toward a neurocircuit-based taxonomy to guide treatment of obsessive-compulsive disorder

An important challenge in mental health research is to translate findings from cognitive neuroscience and neuroimaging research into effective treatments that target the neurobiological alterations involved in psychiatric symptoms. To address this challenge, in this review we propose a heuristic neurocircuit-based taxonomy to guide the treatment of obsessive-compulsive disorder (OCD). We do this by integrating information from several sources. First, we provide case vignettes in which patients with OCD describe their symptoms and discuss different clinical profiles in the phenotypic expression of the condition. Second, we link variations in these clinical profiles to underlying neurocircuit dysfunctions, drawing on findings from neuropsychological and neuroimaging studies in OCD. Third, we consider behavioral, pharmacological, and neuromodulatory treatments that could target those specific neurocircuit dysfunctions. Finally, we suggest methods of testing this neurocircuit-based taxonomy as well as important limitations to this approach that should be considered in future research.

Pharmacotherapeutic Strategies and New Targets in OCD

Effective pharmacological and psychotherapeutic treatments are well established for obsessive-compulsive disorder (OCD). Serotonin reuptake inhibitors (SRIs) are first-line treatment and are of benefit to about half of patients. Augmentation of SRI treatment with low-dose neuroleptics is an evidence-based second-line strategy. Specialty psychotherapy is also used as both first-line and second-line treatment and can benefit many. However, a substantial number of patients do not respond to these treatments. New alternatives are urgently needed. This review summarizes evidence for these established pharmacotherapeutic strategies, and for others that have been investigated in refractory disease but are not supported by the same level of evidence. We focus on three neurotransmitter systems in the brain: serotonin, dopamine, and glutamate. We summarize evidence from genetic, neuroimaging, animal model, and other lines of investigation that probe these three systems in patients with OCD. We also review recent work on predictors of response to current treatments. While many studies suggest abnormalities that may provide insight into the pathophysiology of the disorder, most studies have been small, and non-replication of reported findings has been common. Nevertheless, the gradual accrual of evidence for neurotransmitter dysregulation may in time lead the way to new pharmacological strategies.