L-carnosine as an adjuvant to fluvoxamine in treatment of obsessive compulsive disorder: A randomized double-blind study

Carnosine/histidine-containing dipeptide supplementation improves depression and quality of life: systematic review and meta-analysis of randomized controlled trials

CONTEXT

Mental ill-health is a common and growing issue, affecting 1 in 8 individuals or 970 million people worldwide in 2019. Histidine-containing dipeptides (HCDs) have been suggested to mitigate some aspects of mental ill-health, but a quantitative synthesis of the evidence is lacking. Therefore, a systematic review and meta-analysis of randomized controlled trials was conducted.

OBJECTIVE

To summarize the evidence on the effects of HCDs on mental health outcomes.

DATA SOURCE

A systematic literature search was performed using electronic databases (Medline via Ovid, Embase via Ovid, Scopus, Google Scholar, and Cochrane) from inception to October, 2022.

DATA EXTRACTION

Two authors independently extracted data using a structured extraction format.

DATA ANALYSIS

Data analysis was performed using STATA version 17. Random-effects models were used, and heterogeneity was assessed using the I2 test. Quality appraisal was performed using the Cochrane risk-of-bias 2.0 tool and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach.

CONCLUSION

5507 studies were identified, with 20 studies fulfilling the inclusion criteria. Eighteen studies comprising 776 participants were included in the meta-analysis. HCD supplementation (anserine/carnosine, l-carnosine, β-alanine) caused a significant reduction in depression scores measured with the Becks Depression Inventory (-0.79; 95% CI: -1.24, -0.35; moderate certainty on GRADE) when compared with placebo. An increase in quality-of-life scores measured with the 36-item Short-Form survey (SF-36) (0.65; 95% CI: 0.00, 1.30) and low certainty on GRADE in HCDs (anserine/carnosine, l-carnosine, β-alanine) when compared with placebo were found. However, the rest of the outcomes did not show a significant change between HCD supplementation and placebo. Although the number of studies included in the meta-analysis was modest, a significant mean reduction was observed in depression score as well as an increase in quality-of-life score for the HCD group when compared with placebo. Most of the studies included had small sample sizes with short follow-up periods and moderate to high risk of bias, highlighting the need for further, well-designed studies to improve the evidence base.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42017075354.

Glutamatergic Medications for Obsessive-Compulsive and Related Disorders: A Systematic Review and Meta-Analysis

Importance

Obsessive-compulsive and related disorders (OCRDs) encompass various neuropsychiatric conditions that cause significant distress and impair daily functioning. Although standard treatments are often effective, approximately 60% of patients may not respond adequately, underscoring the need for novel therapeutic approaches.

Objective

To evaluate improvement in OCRD symptoms associated with glutamatergic medications as monotherapy or as augmentation to selective serotonin reuptake inhibitors, with a focus on double-blind, placebo-controlled randomized clinical trials (RCTs).

Data Sources

Electronic searches were conducted in PubMed, Embase, PsycINFO, Web of Science, and Cochrane Central Register of Controlled Trials on October 16, 2024, without date limits.

Study Selection

Two investigators independently screened records to identify double-blind RCTs comparing glutamatergic medications with placebo for patients with OCRDs regardless of age, sex, gender, or refractoriness. Abstracts, study protocols, non-English studies, and trials involving augmentation to psychotherapy were excluded.

Data Extraction and Synthesis

Data were extracted and synthesized using random-effects meta-analyses. Subgroup analysis was conducted based on type of OCRD, population, refractoriness of OCRD, augmentation strategy, risk of bias, and type of glutamatergic medication. Sensitivity analysis was performed using a leave-one-out approach.

Main Outcomes and Measures

Improvement in OCRD symptoms was measured by standardized mean difference (Cohen d). Improvement in obsessive-compulsive disorder (OCD) symptoms was measured by mean difference (reduction in Yale-Brown Obsessive Compulsive Scale [Y-BOCS] scores).

Results

A total of 27 RCTs (1369 participants; mean [SD] age, 31.5 [7.8] years; 65.6% female) were included. Glutamatergic medications showed a large effect size in improving OCRD symptoms (Cohen d = -0.80 [95% CI, -1.13 to -0.47]; low certainty of evidence). In the 23 OCD-specific RCTs, glutamatergic medications demonstrated a significant mean reduction in Y-BOCS scores (mean difference, -4.17 [95% CI, -5.82 to -2.52]; moderate certainty of evidence).

Conclusions and Relevance

These findings indicate that glutamatergic medications may be effective in treating OCRDs, particularly OCD. However, high heterogeneity and potential publication bias necessitate cautious interpretation. Further research with larger sample sizes is needed to explore dose-dependent effects, additional OCRD subtypes, and other promising glutamatergic medications.

Efficacy and safety of 5-hydroxytryptamine-3 (5-HT3) receptor antagonists in augmentation with selective serotonin reuptake inhibitors (SSRIs) in the treatment of moderate to severe obsessive-compulsive disorder: a systematic review and meta-analysis of randomized clinical trials

Obsessive-compulsive disorder (OCD) is the fourth most common mental disorder, and selective serotonin reuptake inhibitors (SSRIs) are the cornerstone of its pharmacological treatment. About 40-60% of the cases are treatment-refractory, and this makes searching for second-line treatment necessary. 5-Hydroxytryptamine-3 (5-HT3) antagonists are among the many medications that have been used in augmentation with SSRIs. In this systematic review and meta-analysis, we assessed the efficacy and safety of 5-HT3 receptor antagonists in augmentation with SSRIs in treating moderate to severe OCD. We searched PubMed, Web of Science, Scopus, Cochrane library, and Google Scholar for relevant trials published up to December 2022. The effect size was the mean difference in Yale-Brown obsessive compulsive scale (Y-BOCS) scores before and after receiving 5-HT3 receptor antagonist drugs in augmentation with SSRIs in moderate to severe OCD patients. We included 6 randomized-controlled trails (RCTs) with 334 patients assessing the effect of the augmentation of SSRIs with ondansetron, granisetron, and tropisetron on treating moderate to severe OCD. Our results were in favor of the experimental group in total (Z = 8.37, P < 0.00001), in the compulsion subgroup (Z = 5.22, P < 0.00001), and in the obsession subgroup (Z = 8.33, P < 0.00001). They are well-tolerated, and have mild side effects and do not result in withdrawal. Augmentation of 5-HT3 antagonists with SSRIs can be beneficial in treating moderate to severe OCD. Further multi-center trials under adequate conditions in longer periods are needed to help come up with a comprehensive action plan.

Agomelatine augmentation of sertraline in the treatment of moderate to severe obsessive-compulsive disorder: a randomized double-blinded placebo-controlled clinical trial

BACKGROUND

As 40-60% of the patients with obsessive-compulsive disorder (OCD) do not adequately respond to the first-line treatment, finding an effective second-line treatment is required. Our aim was to assess the efficacy and safety of agomelatine (a selective melatonin receptor agonist and a 5-hydroxytryptamine (HT)2 C antagonist) augmentation of sertraline in the treatment of patients with moderate to severe OCD.

METHODS

In this 12-week randomized, double-blinded, placebo-controlled, parallel-group clinical trial, 65 patients with moderate to severe OCD according to the Diagnostic and Statistical Manual of Mental Disorders-Fifth edition (DSM-5) criteria and a Yale-Brown obsessive compulsive scale (Y-BOCS) score of over 21, were included. They were assigned with sertraline (100 mg/day for the first 4 weeks and 200 mg/day for the next 8 weeks) and either agomelatine (25 mg/day) or placebo. The primary outcome was OCD symptoms measured by the Y-BOCS.

RESULTS

Fifty patients (24 in agomelatine group and 26 in placebo group) completed the trial. The Y-BOCS scores in total (MD (95% CI) = 12.25 (11.00, 13.49) (P < 0.001) vs. MD (95% CI) = 12.46 (6.65, 15.74) (P < 0.001)), the obsession subscale (MD (95% CI) = 5.04 (4.19, 5.88) (P < 0.001) vs. MD (95% CI) = 5.00 (3.84, 6.16) (P = 0.0001)), and compulsion subscale (MD (95% CI) = 7.21 (6.34, 8.07) (P < 0.001) vs. MD (95% CI) = 7.460 (6.50, 8.42) (P < 0.001)) significantly decreased in both groups. Although, at the end of the trial, no significant difference was observed between the scores of the two groups in total (MD (95% CI) = 0.480 (-1.23, 2.19) (P = 0.78)), the obsession subscale (MD (95% CI) = 1.020 (-0.15, 2.19) (P = 0.38)), and the compulsion subscale (MD (95% CI) = 0.540 (-0.34, 1.42) (P = 0.54)). No major adverse effects were recorded, and the frequency of side effects was not significantly different between the groups.

CONCLUSION

Agomelatine in augmentation with sertraline is safe and tolerable in patients with moderate to severe OCD. However, our study does not support its efficacy in improving OCD symptoms, compared to placebo.

TRIAL REGISTRATION

The trial was registered at the Iranian Registry of Clinical Trials on 14/07/2020 ( www.irct.ir ; IRCT ID: IRCT20170123032145N5).

L-theanine combination therapy with fluvoxamine in moderate-to-severe obsessive-compulsive disorder: A placebo-controlled, double-blind, randomized trial

AIM

The main aim of this study was to investigate the additional effects of L-theanine, an amino acid in tea and an analog of glutamate with neuroprotective and anti-depressant properties, on obsessive-compulsive disorder (OCD) symptoms in combination with fluvoxamine.

METHODS

Patients from either sex aged between 18 and 60 years diagnosed with OCD, based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), who had a Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score of more than 21 were enrolled in a double-blinded, parallel-group, placebo-controlled, clinical trial of 10 weeks to receive either L-theanine (100 mg twice daily) and fluvoxamine (100 mg daily initially followed by 200 mg daily after week 5) or placebo and fluvoxamine. The primary outcome of interest in this study was the Y-BOCS total score decrease from baseline.

RESULTS

From a total of 95 evaluated patients, 50 completed our study; 30 were randomly assigned to each group. Multivariate analysis (ANOVA) showed a significant effect of time× $$ \times $$ treatment for L-theanine in obsession subscale (F = 5.51, P = 0.008) of the Y-BOCS score but not in the total and compulsion scores. Our results showed significantly more improvement in obsession subscale scores in L-theanine compared to placebo group (P = 0.007, Cohen's d = 0.82). Also, total Y-BOCS scores were lower in L-theanine compared to placebo group at week 5 (P = 0.039, Cohen's d = 0.60) and 10 (P = 0.008, Cohen's d = 0.80). However, there was no significant between-group differences in compulsion subscale scores. Complete response was also more frequent in the L-theanine group (P = 0.0001).

CONCLUSION

Findings in this study suggest L-theanine as a relatively safe and effective adjuvant therapy for moderate to severe OCD.

Mitochondrial dysfunction in cognitive neurodevelopmental disorders: Cause or effect?

Mitochondria have a crucial role in brain development and neurogenesis, both in embryonic and adult brains. Since the brain is the highest energy consuming organ, it is highly vulnerable to mitochondrial dysfunction. This has been implicated in a range of brain disorders including, neurodevelopmental conditions, psychiatric illnesses, and neurodegenerative diseases. Genetic variations in mitochondrial DNA (mtDNA), and nuclear DNA encoding mitochondrial proteins, have been associated with several cognitive disorders. However, it is not yet clear whether mitochondrial dysfunction is a primary cause of these conditions or a secondary effect. Our review article deals with this topic, and brings out recent advances in mitochondria-oriented therapies. Mitochondrial dysfunction could be involved in the pathogenesis of a subset of disorders involving cognitive impairment. In these patients, mitochondrial dysfunction could be the cause of the condition, rather than the consequence. There are vast areas in this topic that remains to be explored and elucidated.

Serum levels of carnosine may be associated with the duration of MDD episodes

BACKGROUND

Major depressive disorder (MDD) is a recurrent disorder that incurs a high societal burden. However, the etiology of MDD remains unclear. The functioning of several systems associated with the etiopathogenesis of MDD, such as inflammatory and stress systems, is partially modulated by the dipeptide carnosine.

METHODS

The study comprised 99 MDD patients and 253 non-depressed controls aged 20-71 years. Fasting serum samples were analyzed using ultra-performance liquid chromatography coupled to mass spectrometry to determine the serum levels of carnosine and its constituent, histidine. We compared these metabolites in three different settings: 1) MDD patients vs. non-depressed controls and 2) remitted vs. non-remitted MDD patients, as well as 3) changes in the metabolite levels during the follow-up period within a) the remitted group and b) the non-remitted group. In addition, we assessed the possible effect of medications on the measured metabolites.

RESULTS

We observed higher serum levels of carnosine in the MDD group compared to the control group at baseline (OR = 1.895, 95%CI = 1.223-2.937, p = 0.004). Elevated serum levels of carnosine were also associated with a longer duration of the depressive episode (Z = 0.406, p = 0.001). However, the use of any antipsychotic medication (n = 36) was associated with lowered carnosine levels (p = 0.010 for use vs. non-use). At the follow-up, remitted and non-remitted participants displayed no significant differences in their carnosine levels (Z = -0.14, p = 0.891) or histidine (Z = -1.39 p = 0.164).

CONCLUSIONS

An increase in circulating carnosine may characterize depressive episodes and may represent a protective homeostatic reaction against MDD-related oxidative stress and inflammation.

Granisetron-mediated augmentation of sertraline therapeutic effect in obsessive-compulsive disorder: a double-blind placebo-controlled, randomized clinical trial

BACKGROUND

Medications currently recommended for the treatment of Obsessive-Compulsive Disorder (OCD) usually relieve the severity of symptoms by as much as 20-30%, and satisfactory treatment is obtained in 40-60% of patients with OCD. Nevertheless, the remaining symptoms continue to impair the patients' function. Therefore, it is necessary to investigate possible strategies to improve the mitigation of symptoms. In this study, the main objective was to examine and investigate the effectiveness of granisetron, which is a serotonin 5-hydroxytryptamine receptor type 3 (5-HT₃) antagonist, as an adjunct therapy to selective serotonin reuptake inhibitors, for the purpose of ameliorating OCD symptoms.

METHODS

fifty-eight patients diagnosed with OCD, based on Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria, who had a Yale-Brown obsessive-compulsive scale (Y-BOCS) score of more than 21 were recruited in a double-blinded, parallel-group, placebo-controlled, clinical trial of 10 weeks to receive either granisetron (1 mg twice daily) and sertraline (100 mg daily initially followed by 200 mg daily after week 4) or placebo and sertraline. The primary outcome was OCD symptoms measured by the Y-BOCS.

RESULTS

Y-BOCS total score significantly dropped in both groups (28.9 to 17.7 for granisetron plus sertraline and 27.5 to 19.3 for placebo plus sertraline group with a slightly greater drop for granisetron plus sertraline group), while the granisetron plus sertraline group experienced a significantly greater reduction in obsession scores (Greenhouse-Geisser F(2.32,97.57) = 4.52,p-value = 0.01). Moreover, in comparison with the placebo plus sertraline group, the proportion of the patients showing complete response was considerably higher among the granisetron plus sertraline group (P-value < 0.01). No major adverse effects were observed in any of the groups.

CONCLUSION

The results suggest that granisetron augmentation of sertraline may increase the rate of response in patients with moderate to severe non-refractory OCD. Further studies are suggested in this regard.

The effect of low-frequency repetitive transcranial magnetic stimulation on left dorsolateral prefrontal cortex in patients with the obsessive-compulsive disorder: a double-blinded, sham-controlled clinical trial

Background

Obsessive-compulsive disorder (OCD) is a complicated neuropsychiatric disorder, which its prevalence ranges from 2 to 4%. In 30–60% of patients due to intolerance of side effects or partial response to treat symptoms of the disease remain or relapse. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive therapeutic option to treat this condition. Transcranial magnetic stimulation can be applied for treating with no anesthesia. The current study intended to evaluate the effectiveness of low-frequency rTMS on the left dorsolateral prefrontal cortex as an adjunct treatment in combination with standard medication in patients with OCD.

Results

In both groups of intervention and sham, the Y-BOCS scale was decreased. There was no significant difference between the two groups (P=0.82). Also after 15 sessions, the symptoms of OCD patients were improved. Although the treatment process was the same in the control group, none of the patients showed any serious complications, such as seizures, severe headache, neurological complication, or cognitive impairment during treatment.

Conclusions

It seems that treatment with 1 Hz rTMS on the left dorsolateral prefrontal cortex does not play an effective role in the recovery of OCD patients.

Trial registration

Name of the registry: Therapeutic effect comparison of the Repetitive Transcranial MagneticMagnetic Stimulation (RTMS) combination therapy with drug versus medication monotherapy in obsessive-compulsive disorder (OCD). Trial registration number: IRCT ID: IRCT20200728048240N1. Date of registration: 2020/8/8.

Oral Supplementation with L-Carnosine Attenuates Social Recognition Deficits in CD157KO Mice via Oxytocin Release

The outcomes of supplementation with L-carnosine have been investigated in clinical trials in children with autism spectrum disorder (ASD). However, reports on the effects of L-carnosine in humans have been inconsistent, and the efficacy of L-carnosine supplementation for improving ASD symptoms has yet to be investigated in animal studies. Here, we examined the effects of oral supplementation with L-carnosine on social deficits in CD157KO mice, a murine model of ASD. Social deficits in CD157KO mice were assessed using a three-chamber social approach test. Oral supplementation with L-carnosine attenuated social behavioral deficits. The number of c-Fos-positive oxytocin neurons in the supraoptic nucleus and paraventricular nucleus was increased with L-carnosine supplementation in CD157KO mice after the three-chamber social approach test. We observed an increase in the number of c-Fos-positive neurons in the basolateral amygdala, a brain region involved in social behavior. Although the expression of oxytocin and oxytocin receptors in the hypothalamus was not altered by L-carnosine supplementation, the concentration of oxytocin in cerebrospinal fluid was increased in CD157KO mice by L-carnosine supplementation. These results suggest that L-carnosine supplementation restores social recognition impairments by augmenting the level of released oxytocin. Thus, we could imply the possibility of a safe nutritional intervention for at least some types of ASD in the human population.

Memantine augmentation of sertraline in the treatment of symptoms and executive function among patients with obsessive-compulsive disorder: A double-blind placebo-controlled, randomized clinical trial

BACKGROUND

Medications currently recommended for the treatment of Obsessive-Compulsive Disorder (OCD) usually decrease the severity of the symptoms by 20-30%; however, 40-60% of OCD patients do not achieve a satisfactory response. Our main objective was to investigate the effectiveness of memantine, a non-competitive N-Methyl-D-aspartate (NMDA) receptor antagonist, as an adjunct therapy to sertraline, a selective serotonin reuptake inhibitor (SSRI), to improve severity of symptoms and executive function among patients with obsessive-compulsive disorder.

METHODS

Seventy patients with OCD according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria, and a Yale-Brown obsessive compulsive scale (Y-BOCS) score of more than 21 were recruited to the study. They received sertraline (100 mg daily initially followed by 200 mg daily after week 4) and either memantine (10 mg twice daily) or placebo in a placebo controlled, double-blinded, parallel-group, clinical trial of 12 weeks. The primary outcome was OCD symptoms measured by the Y-BOCS. Moreover, executive function of participants was measured by the Wisconsin Card Sorting Test (WCST).

RESULTS

The total score, and obsession and compulsion subscales of Y-BOCS significantly dropped in both groups with no significant difference between the two groups. However, memantine group showed a greater response in the number of completed categories subscale of the WCST (p value<0.001). We did not observe any major adverse effects in any of the groups.

CONCLUSION

Memantine has an acceptable safety and tolerability in patients with OCD and might have a positive effect on their executive function. Nevertheless, the current results don`t support the efficacy of memantine as an adjunctive agent to sertraline for symptoms in patients with OCD.

TRIAL REGISTRATION

The trial was registered at the Iranian Registry of Clinical Trials on 04/10/2019 ( www.irct.ir ; IRCT ID: IRCT20170123032145N4).

Glutamatergic medications as adjunctive therapy for moderate to severe obsessive-compulsive disorder in adults: a systematic review and meta-analysis

BACKGROUND

Obsessive-compulsive disorder (OCD) is among the most disabling neuropsychiatric conditions characterized by the presence of repetitive intrusive thoughts, impulses, or images (obsessions) and/or ritualized mental or physical acts (compulsions). Serotonergic medications, particularly Selective Serotonin Reuptake Inhibitors (SSRIs), are the first-line treatments for patients with OCD. Recently, dysregulation of glutamatergic system has been proposed to be involved in the etiology of OCD. We designed this systematic review and meta-analysis to evaluate clinical efficacy of glutamatergic medications in patients with OCD, according to the guidelines of Cochrane collaboration.

METHOD

We searched Medline, Scopus, and Cochrane library without applying any language filter. Two of the authors independently reviewed search results for irrelevant and duplicate studies and extracted data and assessed methodological quality of the studies. We transformed data into a common rubric and calculated a weighted treatment effect across studies using Review Manager.

RESULTS

We found 476 references in 3 databases, and after exclusion of irrelevant and duplicate studies, 17 studies with total number of 759 patients with OCD were included. In the present review we found evidence for several drugs such as memantine, N-acetylcysteine (NAC), Minocycline, L-carnosine and riluzole. Glutamaterigic drug plus SSRIs were superior to SSRI+ Placebo with regard to Y-BOCS scale [standardized mean difference (SMD = - 3.81 95% CI = - 4.4, - 3.23).

CONCLUSION

Augmentation of glutamatergic medications with SSRIs are beneficial in obsessive-compulsive patients, no harmful significant differences in any safety outcome were found between the groups.

Lifestyle Interventions in the Treatment of Obsessive-Compulsive and Related Disorders: A Systematic Review

OBJECTIVE

Lifestyle medicine is increasingly important in psychiatry for its efficacy as a transdiagnostic treatment, its preventative potential, and its increased tolerability compared with first-line strategies. Although the impact of lifestyle medicine is strong across many psychiatric illnesses, our understanding of the effectiveness of lifestyle interventions in treating obsessive-compulsive and related disorders (OCRDs) is minimal. We aimed to conduct a systematic review examining the effect of lifestyle interventions (targeting diet, exercise, sleep, stress management, and tobacco/alcohol use) on OCRD symptoms.

METHODS

We systematically searched four electronic databases for published randomized controlled trials reporting on lifestyle interventions for OCRDs. We qualitatively synthesized results of eligible studies and calculated mean changes in symptom severity from baseline to end point and standardized between-group effect sizes.

RESULTS

We identified 33 eligible studies. Poor efficacy was noted across a number of rigorous dietary supplement interventions with some promising data in four (of six) studies regarding N-acetylcysteine for trichotillomania, skin picking, and obsessive-compulsive disorder. Stress management interventions, generally characterized by high risk of bias, reported mild effectiveness with greater effects noted for mind-body exercises (yoga) for obsessive-compulsive disorder. Greater improvements may be achieved when lifestyle intervention is adjunct to first-line treatments and delivered by facilitators.

CONCLUSIONS

Diet (particularly N-acetylcysteine) and stress management interventions seem promising avenues for OCRDs treatment. We present an action plan to move the lifestyle interventions for OCRDs field forward. Further high-quality lifestyle interventions are required to improve the certainty of findings and to inform clinical treatment guidelines.Review Registration Number: CRD42020151407.

Effects of Celecoxib Adjunct to Selective Serotonin Reuptake Inhibitors on Obsessive-Compulsive Disorder

Introduction:

Inflammatory processes in the brain play an important role in the etiopathogenesis of Obsessive-Compulsive Disorder (OCD). Cyclooxygenase inhibitors, such as celecoxib reduce the production of proinflammatory cytokines. This double-blind study aimed to investigate the effects of adding celecoxib to Selective Serotonin Reuptake Inhibitors (SSRIs)on treating OCD.

Methods:

Sixty patients who met the diagnosis criteria for OCD based on the Diagnostic and Statistical Manual of Mental Disorders -Fourth Edition- Text Revision (DSM-IV-TR) were recruited in the present study. Two psychiatrists independently confirmed the diagnosis by performing structured interviews. The study participants included 23 patients who received SSRIs and celecoxib (400 mg twice daily) and 22 patients in the control group that received SSRIs and placebo. Moreover, at baseline, in weeks 4, 8, and 12, the explored patients were assessed by a psychiatrist using the Yale-Brown Obsessive-Compulsive Scale (Y-BCOS).

Results:

A significant difference was observed in the change of scores on the Y-BOCS in week 12, compared with the onset of the study between the study groups (t= −8.976, df=38, P=0.001). There was a significant difference between the study groups in obsession (F= 49.19, df= 1, P≤0.001), compulsion (F= 13.78, df= 1, P= 0.001), and OCD (F= 57.25, df= 1, P≤0.001), i.e., higher in the celecoxib group.

Conclusion:

This study showed that adjuvant treatment with celecoxib can further improve the symptoms of OCD in individuals receiving SSRIs.

The Role of Antioxidants in the Management of Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a chronic neuropsychiatric disorder that has a significant effect on the quality of life. The most effective treatment for OCD is the combination of selective serotonin reuptake inhibitors (SSRI) with cognitive behavior therapy (CBT). However, several adverse effects have been linked with this usual pharmacotherapy, and it is unsuccessful in many patients. The exact pathophysiology of OCD is not completely known, though the role of oxidative stress in its pathogenesis has been proposed recently. This review presents an overview of animal and human studies of antioxidant treatment for OCD. The use of antioxidants against oxidative stress is a novel treatment for several neurodegenerative and neuropsychiatric disorders. Among antioxidants, NAC was one of the most studied drugs on OCD, and it showed a significant improvement in OCD symptoms. Thus, antioxidants could be promising as an adjuvant treatment for OCD. However, a limited number of human studies are conducted on these agents, and for better judgment, human studies with a large sample size are necessary.

Investigational and Experimental Drugs to Treat Obsessive-Compulsive Disorder

Treatment-resistance is a frequent condition for obsessive-compulsive disorder (OCD). Over the past decades, a lot of effort has been made to address this issue, and several augmentation strategies of serotonergic drugs have been investigated. Antidopaminergic drugs are considered the first choice as augmentation strategy for treatment-resistant OCD patients, but they seem to work only for a subset of patients, and none of them have been officially approved for OCD. Recently, the role of glutamate and inflammation in OCD pathophysiology clearly emerged, and this has led to several investigations on glutamatergic and anti-inflammatory agents. Results seem promising but still inconclusive. Probiotic interventions (considered to modulate the immune systems and the brain activity) are gaining attention in several psychiatric fields but are still at their early stages in the OCD field. Research on new treatment approaches for OCD is moving forward, and more than one hundred interventional trials are ongoing around the world. While the vast majority of these trials involve neuromodulation and psychotherapeutic approaches, only a small proportion (around 20%) involve the investigation of new pharmacological approaches (tolcapone, nabilone, psilocybin, troriluzole, nitrous oxide, rituximab, naproxen, and immunoglobulins). Here, we provide a comprehensive review of investigational and experimental drugs to treat OCD.

5-Hydroxytryptophan as adjuvant therapy in treatment of moderate to severe obsessive-compulsive disorder: a double-blind randomized trial with placebo control

On the basis of numerous previous studies, the serotonergic system plays a role in the pathogenesis of obsessive-compulsive disorder (OCD) and effective agents in this pathway, such as 5-hydroxytryptophan, can potentially contribute to treatment of patients with this disorder. Evaluating the efficacy of 5-hydroxytryptophan in treating OCD was the aim of the present randomized, double-blind, placebo-controlled 12-week trial. In a 12-week, randomized double-blind study, 60 patients with a Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition diagnosis of moderate to severe OCD and a Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score of >21 were randomly assigned to receive either fluoxetine plus placebo or fluoxetine plus 5-hydroxytryptophan (100 mg twice daily). All patients, regardless of their treatment group, received fluoxetine at 20 mg/day for the initial 4 weeks of the study followed by 60 mg/day of fluoxetine for the rest of the trial course. Symptoms were assessed using the Y-BOCS at baseline and weeks 4, 8 and 12. General linear model repeated measure showed significant effects for time × treatment interaction on total Y-BOCS (F = 12.07, df = 2.29, P-value <0.001), obsession (F = 8.25, df = 1.91, P-value = 0.001) and compulsion subscale scores (F = 6.64, df = 2.01, P-value = 0.002). 5-Hydroxytryptophan augmentation therapy demonstrated higher partial and complete treatment response rate (P = 0.032 and P = 0.001, respectively) according to the Y-BOCS total scores. The results of this study confirm that 5-hydroxytryptophan may be effective as an augmentative agent in treatment of moderate-to-severe OCD.

L-Carnosine combination therapy for major depressive disorder: A randomized, double-blind, placebo-controlled trial

BACKGROUND

Evidence for antidepressant effects of L-Carnosine was shown in some experimental studies. In this study we tried to evaluate the efficacy and tolerability of L-Carnosine combination therapy in treatment of patients with major depressive disorder (MDD).

METHODS

Fifty-eight patients with MDD (DSM-V) and Hamilton Depression Rating Scale (HAM-D) score ≥ 19 were randomized to receive either 400 mg twice daily L-Carnosine or placebo in addition to citalopram (maximum dosage of 40 mg/day) for six weeks in a randomized double-blind, and placebo-controlled study. Patients were assessed using the HAM-D scale at baseline and weeks 2, 4, and 6.

RESULTS

Fifty-two patients completed the trial. General linear model repeated measure showed significant difference for time × treatment on HAM-D score [F = 3.17, df = 2.39, p-value = 0.03]. Significantly greater improvement was detected in HAM-D score of the L-Carnosine group compared with the placebo group from baseline to weeks 2, 4 and 6 [Ps = 0.013, 0.028 and 0.023; respectively]. Patients in the L-Carnosine group experienced significantly greater response and remission rate than the placebo group [Ps = 0.023 and 0.012; respectively]. There was no significant difference between the two groups in baseline parameters and frequency of side effects.

LIMITATIONS

Short follow-up period and small population size were two important limitations of this study.

CONCLUSIONS

L-Carnosine combination therapy with citalopram can effectively improve symptoms of patients with major depressive disorder. Rapid-onset antidepressant effects of L-Carnosine were also shown which need further investigation.

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.

Placebo Effect in Obsessive-Compulsive Disorder (OCD). Placebo Response and Placebo Responders in OCD: The Trend Over Time

BACKGROUND

Placebo response appears to be increasing in antidepressant, antipsychotic and various internal medicine trials. A similar trend has been reported for OCD during 1989-1999. Placebo response is generally considered as the extent to which placebo treatment is associated with core symptom improvement. In this analysis, we used Joinpoint regression to assess the time trend of both placebo response and placebo responder rates according to the year of publication with no time restriction in OCD drug trials.

METHODS

We included drug and/or psychotherapy trials vs. placebo from PubMed, Embase, CINAHL, and PsycINFO retrieved through the search (placebo OR sham) AND (obsessive* OR OCD). We included studies through investigator consensus. We then performed on data of included studies log-linear joinpoint segmented regression models using a p<0.05 cutoff.

RESULTS

We included 113 studies from 112 published papers. Placebo mean annual response rates in OCD studies significantly increased from 1991 to 2017 with an annual percent change (APC) of 0.66%, while placebo mean annual responder rates also significantly increased from 2010 to 2017, with an APC of 5.45%. Drug mean annual response rates in OCD studies significantly increased from 1987 to 2012 with an APC of 0.72%, while the corresponding responder rates did not show statistically significant APC changes between 1984 and 2017.

CONCLUSION

We observed a tendency for placebo to increase both measures of response in OCD clinical drug trials through the years that tend to approximate the responses shown by drugs. Changes in the type of study (moving from classical head to head comparisons to add-on studies in treatmentresistant populations) and countries involved in experimentation may partially account for some portion of these results. It appears that placebo effects are becoming more elusive and out of control.

The Potential of Carnosine in Brain-Related Disorders: A Comprehensive Review of Current Evidence

Neurological, neurodegenerative, and psychiatric disorders represent a serious burden because of their increasing prevalence, risk of disability, and the lack of effective causal/disease-modifying treatments. There is a growing body of evidence indicating potentially favourable effects of carnosine, which is an over-the-counter food supplement, in peripheral tissues. Although most studies to date have focused on the role of carnosine in metabolic and cardiovascular disorders, the physiological presence of this di-peptide and its analogues in the brain together with their ability to cross the blood-brain barrier as well as evidence from in vitro, animal, and human studies suggest carnosine as a promising therapeutic target in brain disorders. In this review, we aim to provide a comprehensive overview of the role of carnosine in neurological, neurodevelopmental, neurodegenerative, and psychiatric disorders, summarizing current evidence from cell, animal, and human cross-sectional, longitudinal studies, and randomized controlled trials.

Amantadine as adjuvant therapy in the treatment of moderate to severe obsessive-compulsive disorder: A double-blind randomized trial with placebo control

AIM

The role of the glutamatergic system in the pathogenesis of obsessive-compulsive disorder (OCD) has been shown by numerous studies. The aim of the present randomized, double-blind, placebo-controlled, 12-week trial was to assess the efficacy and tolerability of amantadine as an adjuvant to fluvoxamine in the treatment of patients with moderate to severe OCD.

METHODS

One hundred patients diagnosed with moderate to severe OCD were randomized into two parallel groups to receive fluvoxamine (100 mg twice a day) plus placebo or fluvoxamine (100 mg twice a day) plus amantadine (100 mg daily) for 12 weeks. All patients received 100 mg/day fluvoxamine for 28 days followed by 200 mg/day for the rest of the trial, regardless of their treatment groups. Patients were evaluated for response to treatment using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) at baseline and at Weeks 4, 10, and 12. The main outcome measure was to assess the efficacy of amantadine in improving the OCD symptoms.

RESULTS

Repeated-measure analysis of variance showed a significant effect for Time × Treatment interaction (Greenhouse-Geisser corrected: F = 3.84, d.f. = 1.50, P = 0.03) in the Y-BOCS total score and a significant effect for Time × Treatment interaction (Greenhouse-Geisser corrected: F = 5.67, d.f. = 1.48, P < 0.01) in the Y-BOCS Obsession subscale score between the two groups.

CONCLUSION

The results of this study suggest that amantadine may be effective as an augmentative agent in the treatment of moderate-to-severe OCD.

Current and up-and-coming pharmacotherapy for obsessive-compulsive disorder in adults

INTRODUCTION

Only 40-60% of obsessive-compulsive patients respond to first line treatments, such as selective serotonin reuptake inhibitors (SSRIs) and cognitive-behavioral therapy. Several second-line treatments have been investigated in the last two decades, and most of them seem to work, at least in a subset of patients. However, since there is still a lack of treatment predictors, the treatment of obsessive-compulsive disorder (OCD) is still empirical and non-evidence based.

AREAS COVERED

In this paper, we review current and up-and-coming pharmacotherapy for OCD in adults, focusing on two emerging fields of research, inflammation and glutamate systems, since they have attracted the greatest attention in recent years in OCD pharmacological research.

EXPERT OPINION

Most of the investigated second-line agents seem to work at least in a subset of patients with OCD. These results raise an open question: what works for who? In our opinion, this question should be answered in a precision medicine perspective or, in other words, individualizing diagnostic processes and treatment approaches. In a precision medicine approach, OCD treatment should be sub-type specific, phase specific, multimodal and sequential, and, more importantly, dimensional.