An Open-Label Trial of Memantine for Cognitive Impairment in Patients with Posttraumatic Stress Disorder

Treatment of Posttraumatic Stress Disorder: A State-of-the-art Review

This narrative state-of-the-art review paper describes the progress in the understanding and treatment of Posttraumatic Stress Disorder (PTSD). Over the last four decades, the scientific landscape has matured, with many interdisciplinary contributions to understanding its diagnosis, etiology, and epidemiology. Advances in genetics, neurobiology, stress pathophysiology, and brain imaging have made it apparent that chronic PTSD is a systemic disorder with high allostatic load. The current state of PTSD treatment includes a wide variety of pharmacological and psychotherapeutic approaches, of which many are evidence-based. However, the myriad challenges inherent in the disorder, such as individual and systemic barriers to good treatment outcome, comorbidity, emotional dysregulation, suicidality, dissociation, substance use, and trauma-related guilt and shame, often render treatment response suboptimal. These challenges are discussed as drivers for emerging novel treatment approaches, including early interventions in the Golden Hours, pharmacological and psychotherapeutic interventions, medication augmentation interventions, the use of psychedelics, as well as interventions targeting the brain and nervous system. All of this aims to improve symptom relief and clinical outcomes. Finally, a phase orientation to treatment is recognized as a tool to strategize treatment of the disorder, and position interventions in step with the progression of the pathophysiology. Revisions to guidelines and systems of care will be needed to incorporate innovative treatments as evidence emerges and they become mainstream. This generation is well-positioned to address the devastating and often chronic disabling impact of traumatic stress events through holistic, cutting-edge clinical efforts and interdisciplinary research.

The Effect of Add-on Memantine in New Onset Combat-Related Posttraumatic Stress Disorder Core Symptoms: A Pilot Study

Objective: Studies using standard neuropsychological instrumentation have shown memory deficits in posttraumatic stress disorder (PTSD) patients. We examined the efficacy and safety of memantine in new cases of combat-related PTSD in the military by conducting a 16-week prospective double-blind randomized controlled trial. Method : Twenty-six new combat-related PTSD cases were recruited from among the military personnel based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Patients were assigned to memantine and Placebo groups. They were monitored at baseline, week eight, and week 16. Memantine was added to each patient's current medication with an initial dosage of 5 mg/day, raised by 5 mg/day every week until it reached the maintenance level of 20 mg/day. The concurrent drugs were essentially kept unchanged during the trial. The primary outcome was PTSD severity as assessed by the Clinician-administered PTSD Scale (CAPS). The CAPS is a valid and reliable tool for the diagnosis of PTSD and measurement of its severity according to the DSM-4. Results: CAPS mean score in baseline (P = 0.811) and weeks eight (P = 0.389) and 16 (P = 0.066) did not show any significant differences between the two groups. The mean CAPS score in the memantine group significantly (P = 0.006) decreased (Mean differences = -8.79) compared to the placebo group, showing that intervention with memantine was effective. The mean total CAPS in weeks eight (Mean differences = -14.21) and 16 (Mean differences = -27) were less than the baseline, which was significantly meaningful (P < 0.001). Conclusion: Findings of this study suggest that add-on memantine can be effective in veteran patients with PTSD. So our data provide useful insight into the management of new cases of combat-related PTSD.

Treatment of post-traumatic stress disorder in people with dementia: a structured literature review

Post-traumatic stress disorder (PTSD) is associated with cognitive dysfunctions and is an independent risk factor for dementia. A recent study has found the prevalence of PTSD in people with dementia is 4.7%-7.8%. However, little is known about the effectiveness of PTSD treatment for people with dementia. The primary aim of the current study is to review previous studies on the treatment of PTSD in people with dementia. A structured literature review was performed using a 'Preferred Reporting Items for Systematic Reviews and Meta-Analyses' analysis in PubMed, Embase, PsycINFO and CINAHL. Two independent researchers screened titles and abstracts. The inclusion criteria were: PTSD symptoms present, diagnosis of dementia, PTSD treatment form described and effects of the treatment mentioned. Articles that matched these criteria were included and content and quality were analyzed. We included nine articles, all case reports, with a total of 11 cases. The discussed treatment options are eye movement desensitisation and reprocessing (EMDR) (n = 3), prolonged exposure (n = 1), cognitive behavioural therapy (n = 1) and pharmacological treatment (n = 4). All articles reported a positive effect of the intervention on several monitored symptoms. Evidence for positive effects and feasibility of EMDR were most reliable, and it was applied in two articles of sufficient quality published in 2018 and 2019. EMDR 'on-the-spot' was described with positive effect in one article in which three cases were discussed. The quality of included papers ranged from insufficient to sufficient. This review shows that people with PTSD and dementia can benefit from PTSD treatment. EMDR, prolonged exposure, acceptance and commitment therapy and pharmacological treatment are applicable in this population. EMDR treatment is most described in this population (n = 5) and shows positive results, and the studies are of sufficient quality (n = 3). Further research in the form of a randomised controlled trial is required to study the effectivity of different treatment interventions in this population.

Centrally acting anticholinergic drug trihexyphenidyl is highly effective in reducing nightmares associated with post-traumatic stress disorder

INTRODUCTION

Following a case study on scopolamine butyl bromide, an anticholinergic drug, we studied the effect of a central anticholinergic drug on post-traumatic stress disorder (PTSD)-related flashbacks and nightmares.

METHODS

We administered trihexyphenidyl (TP) to 34 patients with refractory PTSD-related nightmares and flashbacks (open-label trial [n = 22]; single-blind trial [n = 12]), who had previously received psychiatric treatment for approximately 2-15 years, without therapeutic benefits. The effect of TP was determined using the Clinician-Administered PTSD Scale (CAPS) and the Impact of Event Scale-Revised (IES-R).

RESULTS

Overall, most patients reported an improvement to none or mild on the CAPS for nightmares (88%) and flashbacks (79%).

CONCLUSION

This study is the first to demonstrate the potential efficacy of TP in the treatment of refractory PTSD-related nightmares and flashbacks. Further double-blind, randomized control trials are needed to explore the potential clinical benefits of TP in PTSD.

The efficacy of memantine in the treatment of civilian posttraumatic stress disorder: an open-label trial

Background: Currently, there is a paucity of pharmacological treatment options for posttraumatic stress disorder (PTSD), and the development of a novel pharmacotherapeutic approach has become a matter of great interest. Objective: We conducted a 12-week open-label clinical trial to examine the efficacy and safety of memantine, an N-methyl-D-aspartate receptor antagonist, in the treatment of civilian PTSD. Method: Thirteen adult patients with DSM-IV PTSD, all civilian women, were enrolled. They were monitored at an ambulatory care facility every week until 4 weeks and then every 4 weeks until 12 weeks. Memantine was added to each patient's current medication, with the initial dosage of 5 mg/day and then titrated. Concomitant medications were essentially kept unchanged during the trial. The primary outcome was PTSD diagnosis and severity assessed with the Posttraumatic Diagnostic Scale (PDS). Results: Of the 13 cases, one dropped out and two were discarded due to the protocol deviation, and the analysis was done for the remaining 10. Mean PDS total scores decreased from 32.3 ± 9.7 at baseline to 12.2 ± 7.9 at endpoint, which was statistically significant with a large effect (paired t-test: p = .002, d = 1.35); intrusion, avoidance, hyperarousal symptoms were all significantly improved from baseline to endpoint. Six patients no longer fulfilled the diagnostic criteria of PTSD at endpoint. Some adverse, but not serious, effects possibly related to memantine were observed, including sleep problems, sleepiness, sedation, weight change and hypotension. Conclusions: Memantine significantly reduced PTSD symptoms in civilian female PTSD patients and the drug was well tolerated. Future randomized controlled trials are necessary to verify the efficacy and safety of memantine in the treatment of PTSD.

Recent advances in the neurobiology of posttraumatic stress disorder: A review of possible mechanisms underlying an effective pharmacotherapy

Recent progress in the field of neurobiology supported by clinical evidence gradually reveals the mystery of human brain functioning. So far, many psychiatric disorders have been described in great detail, although there are still plenty of cases that are misunderstood. These include posttraumatic stress disorder (PTSD), which is a unique disease that combines a wide range of neurobiological changes, which involve disturbances of the hypothalamic-pituitary-adrenal gland axis, hyperactivation of the amygdala complex, and attenuation of some hippocampal and cortical functions. Such multiplicity results in differential symptomatology, including elevated anxiety, nightmares, fear retrieval episodes that may trigger delusions and hallucinations, sleep disturbances, and many others that strongly interfere with the quality of the patient's life. Because of widespread neurological changes and the disease manifestation, the pharmacotherapy of PTSD remains unclear and requires a multidimensional approach and involvement of polypharmacotherapy. Hopefully, more and more neuroscientists and clinicians will study PTSD, which will provide us with new information that would possibly accelerate establishment of well-tolerated and effective pharmacotherapy. In this review, we have focused on neurobiological changes regarding PTSD, addressing the most disturbed brain structures and neurotransmissions, as well as discussing in detail the recently taken and novel therapeutic paths.

Enhanced Hypothalamic NMDA Receptor Activity Contributes to Hyperactivity of HPA Axis in Chronic Stress in Male Rats

Chronic stress stimulates corticotrophin-releasing hormone (CRH)-expressing neurons in the paraventricular nucleus (PVN) of the hypothalamus and leads to hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, but the mechanisms underlying this action are unknown. Because chronic stress enhances N-methyl-d-aspartate receptor (NMDAR) activity in various brain regions, we hypothesized that augmented NMDAR activity contributes to the hyperactivity of PVN-CRH neurons and the HPA axis in chronic stress. We performed whole-cell patch-clamp recordings on PVN-CRH neurons expressing CRH promoter-driven enhanced green fluorescent protein in brain slices from rats exposed to chronic unpredictable mild stress (CUMS) and unstressed rats. CUMS rats had significantly higher expression levels of the NMDAR subunits GluN1 in the PVN than unstressed rats. Furthermore, puff NMDA-elicited currents, evoked NMDAR currents, and the baseline frequency of the miniature excitatory postsynaptic currents (mEPSCs) in PVN-CRH neurons were significantly larger in CUMS rats than in unstressed rats. The NMDAR-specific antagonist 2-amino-5-phosphonopentanoic acid (AP5) significantly decreased the frequency of mEPSCs of PVN-CRH neurons in CUMS rats but did not change the frequency or amplitude of mEPSCs in unstressed rats. Bath application of AP5 normalized the elevated firing activity of PVN-CRH neurons in CUMS rats but not in unstressed rats. In addition, microinjection of the NMDAR antagonist memantine into the PVN normalized the elevated corticosterone (CORT) levels in CUMS rats to the levels in unstressed rats, but did not alter CORT levels in unstressed rats. Our findings suggest that synaptic NMDAR activity is enhanced in CUMS rats and contributes to the hyperactivity of PVN-CRN neurons and the HPA axis.

Effect of the Glutamate NMDA Receptor Antagonist Memantine as Adjunctive Treatment in Borderline Personality Disorder: An Exploratory, Randomised, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Borderline personality disorder (BPD) is a complex, severe and highly stigmatised psychiatric illness. Several lines of evidence highlight the causal link between chronic stress, glucocorticoid response to stress and glutamatergic overactivity as a key event in the pathophysiology of BPD. Therefore, molecular mechanisms capable of regulating glutamate excitotoxicity represent novel and potentially promising treatment targets. Memantine-HCl is a voltage-dependent N-methyl-D-aspartate (NMDA) receptor 'channel blocker' that selectively blocks pathological glutamate overactivity.

OBJECTIVE

The aim of the current study was to determine if memantine can improve BPD symptoms.

METHOD

An 8-week, double-blind, placebo-controlled trial of adjunctive memantine to treatment as usual was conducted. Treatment as usual comprised antidepressants (selective serotonin reuptake inhibitors, tricyclic antidepressants, monoamine oxidase inhibitors, noradrenergic and specific serotonin antagonists and serotonin noradrenaline reuptake inhibitors), mood stabilisers and antipsychotics, as well as psychotherapy and other psychosocial interventions. Sixteen participants received oral placebo while 17 participants received daily oral memantine 10 mg for 7 days, with subsequent titration to daily oral memantine 20 mg. Eligibility criteria included men and women aged between 16-65 years, with a diagnosis of BPD according to the Diagnostic Interview for Borderline Patients. Primary outcome measures included the Zanarini Rating Scale for Borderline Personality Disorder (ZAN-BPD), assessed fortnightly. Secondary measures included an adverse effect questionnaire administered fortnightly to assess adverse effects known to be related to memantine use.

RESULTS

According to intention-to-treat, latent growth curve analyses, a significant change in total score of ZAN-BPD symptom severity was observed in the memantine group at 20 mg/daily across time, compared with placebo (p = 0.02). No adverse effects were significantly more frequent among participants receiving active memantine than among those receiving placebo.

CONCLUSION

Memantine at a 20-mg daily dose is a well tolerated drug that can improve BPD symptomatology and may be a promising novel therapeutic for its treatment. Further studies are needed to explore the efficacy of memantine versus placebo, as well as in comparison with other potential treatments for BPD. ClinicalTrials.gov identifier: NCT02097706.

Memantine improves semantic memory in patients with amnestic mild cognitive impairment: A single-photon emission computed tomography study

Objective This study was performed to assess the efficacy of memantine in patients with amnestic mild cognitive impairment (aMCI). Methods Thirty healthy controls and 45 patients diagnosed with aMCI based on the Petersen criteria were classified into 3 groups. Group 1 comprised patients who received a single memantine dose following examination (n = 25), Group 2 comprised patients who did not receive memantine treatment following examination (n = 20), and Group 3 comprised healthy age-matched volunteers (n = 30). Neuropsychological testing was performed, and the response to memantine was examined at baseline and at 12, 24, and 48 weeks. Single-photon emission computed tomography was performed at baseline and at 48 weeks in patients who received memantine treatment. Results Memantine treatment significantly improved the symptoms of aMCI according to the Wechsler Adult Intelligence Scale-Revised vocabulary subtest, backward digit span, and Blessed Dementia Rating Scale, all of which were recorded for the duration of the study. Conclusion These data indicate that patients with aMCI receiving memantine develop an improved semantic memory compared with no treatment. Further studies including larger patient cohorts are necessary to validate these findings.

Converging, Synergistic Actions of Multiple Stress Hormones Mediate Enduring Memory Impairments after Acute Simultaneous Stresses

Stress influences memory, an adaptive process crucial for survival. During stress, hippocampal synapses are bathed in a mixture of stress-released molecules, yet it is unknown whether or how these interact to mediate the effects of stress on memory. Here, we demonstrate novel synergistic actions of corticosterone and corticotropin-releasing hormone (CRH) on synaptic physiology and dendritic spine structure that mediate the profound effects of acute concurrent stresses on memory. Spatial memory in mice was impaired enduringly after acute concurrent stresses resulting from loss of synaptic potentiation associated with disrupted structure of synapse-bearing dendritic spines. Combined application of the stress hormones corticosterone and CRH recapitulated the physiological and structural defects provoked by acute stresses. Mechanistically, corticosterone and CRH, via their cognate receptors, acted synergistically on the spine-actin regulator RhoA, promoting its deactivation and degradation, respectively, and destabilizing spines. Accordingly, blocking the receptors of both hormones, but not each alone, rescued memory. Therefore, the synergistic actions of corticosterone and CRH at hippocampal synapses underlie memory impairments after concurrent and perhaps also single, severe acute stresses, with potential implications to spatial memory dysfunction in, for example, posttraumatic stress disorder.

SIGNIFICANCE STATEMENT

Stress influences memory, an adaptive process crucial for survival. During stress, adrenal corticosterone and hippocampal corticotropin-releasing hormone (CRH) permeate memory-forming hippocampal synapses, yet it is unknown whether (and how) these hormones interact to mediate effects of stress. Here, we demonstrate novel synergistic actions of corticosterone and CRH on hippocampal synaptic plasticity and spine structure that mediate the memory-disrupting effects of stress. Combined application of both hormones provoked synaptic function collapse and spine disruption. Mechanistically, corticosterone and CRH synergized at the spine-actin regulator RhoA, promoting its deactivation and degradation, respectively, and destabilizing spines. Notably, blocking both hormones, but not each alone, prevented the enduring memory problems after acute concurrent stresses. Therefore, synergistic actions of corticosterone and CRH underlie enduring memory impairments after concurrent acute stresses, which might be relevant to spatial memory deficits described in posttraumatic stress disorder.