Treatment-resistant posttraumatic stress disorder: strategies for intervention

New perspectives in glutamate and anxiety

Anxiety and stress-related disorders, namely posttraumatic stress disorder (PTSD), generalized anxiety disorder (GAD), obsessive-compulsive disorder (ODC), social and specific phobias, and panic disorder, are a major public health issue. A growing body of evidence suggests that glutamatergic neurotransmission may be involved in the biological mechanisms underlying stress response and anxiety-related disorders. The glutamatergic system mediates the acquisition and extinction of fear-conditioning. Thus, new drugs targeting glutamatergic neurotransmission may be promising candidates for new pharmacological treatments. In particular, N-methyl-d-aspartate receptors (NMDAR) antagonists (AP5, AP7, CGP37849, CGP39551, LY235959, NPC17742, and MK-801), NMDAR partial agonists (DCS, ACPC), α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors (AMPARs) antagonists (topiramate), and several allosteric modulators targeting metabotropic glutamate receptors (mGluRs) mGluR1, mGluR2/3, and mGluR5, have shown anxiolytic-like effects in several animal and human studies. Several studies have suggested that polyamines (agmatine, putrescine, spermidine, and spermine) may be involved in the neurobiological mechanisms underlying stress-response and anxiety-related disorders. This could mainly be attributed to their ability to modulate ionotropic glutamate receptors, especially NR2B subunits. The aim of this review is to establish that glutamate neurotransmission and polyaminergic system play a fundamental role in the onset of anxiety-related disorders. This may open the way for new drugs that may help to treat these conditions.

A qualitative investigation of long-term zopiclone use and sleep quality among Vietnam war veterans with PTSD

BACKGROUND

Self-reported sleep difficulties are common among patients with posttraumatic stress disorder (PTSD), but the routine use of hypnosedatives over extended periods is not generally recommended.

OBJECTIVE

To examine the effects of the extended use of zopiclone among a cohort of patients with combat-related PTSD.

METHODS

We conducted a 6-month follow-up cohort study of zopiclone usage characteristics for 26 combat veterans with PTSD. Psychometric and sleep assessments were also conducted at baseline and 6 months.

RESULTS

The mean baseline score obtained on the tranquilizer dependence questionnaire was 20.4 +/- 13.4, below the cutoff score proposed as indicative of a high likelihood of dependence (23 points). Eight (30.7%) subjects exceeded the proposed cutoff score for dependence at baseline. Most (n = 24) subjects reported poor sleep quality at baseline. Actigraphy revealed that the mean sleep efficiency score was 71.2 +/- 13.7% at baseline. A cohort of 13 men was available for inclusion in the follow-up phase of the study. The tranquilizer dependence questionnaire score at follow-up was broadly similar to the baseline score after a further 6 months of zopiclone use (18.9 at baseline compared with 19.9 +/- 2.6 at follow-up). Individual analysis revealed that the tranquilizer dependence scale score increased for 5 subjects and decreased for 8 subjects at follow-up. Four (30.7%) subjects in the follow-up cohort exceeded the proposed cutoff score for dependence at baseline and 6 (46.1%) subjects exceeded it at follow-up. Actigraphy data were consistent across measurements for individual subjects at baseline and follow-up, with similar mean sleep efficiency scores at baseline and after 6 months of treatment with zopiclone (69.6 +/- 12.7% at baseline; 71.33 +/- 19.0% at follow-up). The proportion of relatively poor sleepers (5/13 at baseline and 4/13 at follow-up) remained essentially unchanged.

CONCLUSIONS

Overall, the results of this study suggest that, although the subjects in the follow-up phase of the research continued to use zopiclone on a regular basis for an extended period, the efficacy of this intervention for addressing PTSD-related sleep disturbance was low. Extended treatment with zopiclone may not necessarily be associated with increased risk for dependence. Further robust research to examine the consequences of long-term zopiclone therapy for PTSD-related sleep disturbance is warranted.

An open-label study of mirtazapine as treatment for combat-related PTSD

BACKGROUND

Posttraumatic stress disorder (PTSD) is common among war veterans. Antidepressants are effective in reducing symptoms and associated disability for some patients.

OBJECTIVE

To assess the effectiveness of mirtazapine for combat-related PTSD among veterans treated in an Australian hospital.

METHODS

This open-label prospective study assessed the effectiveness of mirtazapine as empirical treatment for combat-related PTSD. The initial dose was 15 mg at night, titrated against response to 15-45 mg. PTSD symptoms were assessed using the Mississippi Scale for Combat-Related Posttraumatic Stress Disorder and the Clinician-Administered PTSD Scale (CAPS). Subjects also completed the Hospital Anxiety and Depression Scale (HADS). Body weight and biochemical assessments, including fasting blood glucose (FBG), total serum cholesterol, and serum triglycerides, were also measured. Baseline measurements were repeated after 12 weeks.

RESULTS

During the 18-month recruitment phase, 17 subjects were enrolled and 13 completed the protocol. The CAPS measurement decreased from a mean pretreatment score of 87.5 to 64.4 (p = 0.01). In 4 cases, the CAPS score decreased to below the diagnostic cut-point, consistent with a remission of PTSD. The Mississippi scale measurement decreased from a mean pretreatment score of 126.6 to 115.5 (p < 0.01). The mean HADS anxiety score decreased from 15.6 +/- 4.2 to 13.5 +/- 5.6 (p = 0.016), although the proportion of subjects with scores above the diagnostic cut-point remained high. The mean HADS depression score at baseline was not significantly different from the postintervention score. One subject had a postintervention FBG of 155 mg/dL (consistent with diabetes mellitus), which was increased from the baseline level of 83 mg/dL. All subjects experienced an increase in body weight. One subject had an increase in body weight of 8.75 kg (8.4%) from baseline.

CONCLUSIONS

Although small and with methodological limitations, this study suggests that mirtazapine is an effective treatment for combat-related PTSD. Additional research incorporating an appropriately powered, double-blind, placebo-controlled study design is required.

Pharmacologic alternatives to antidepressants in posttraumatic stress disorder: a systematic review

The selective serotonin reuptake inhibitors (SSRIs) are considered the first-line pharmacological treatment for PTSD. However, even when treated with this class of drugs, response rates rarely exceed 60% and less than 20-30% of the patients achieve full remission. The aim of this study was to address this limitation by systematically reviewing the options left for the treatment of PTSD when patients do not respond satisfactorily to or tolerate SSRIs. A systematic review covering all original articles, letters and brief reports published in any language until October 2008 was conducted through searches in the ISI/Web of Science, PubMed and PILOTS databases. The search terms included the pharmacological class of each agent or its generic name plus "PTSD" or "stress disorder" in the title, in the abstract or as a keyword. Sixty-three articles were selected, covering the following categories: antipsychotics, anticonvulsants, adrenergic-inhibiting agents, opioid antagonists, benzodiazepines and other agents. None of the identified agents reached the level A of scientific evidence, 5 reached level B, 7 level C and 13 level D. The non-antidepressant agent with the strongest scientific evidence supporting its use in PTSD is risperidone, which can be envisaged as an effective add-on therapy when patients did not fully benefit from previous treatment with SSRIs. Prazosin, an adrenergic-inhibiting agent, is a promising alternative for cases of PTSD where nightmares and insomnia are prominent symptoms. So far, there is no consistent empirical support for using benzodiazepines in the prevention or in the treatment of PTSD, although these drugs could alleviate some associated non-specific symptoms, such as insomnia or anxiety. Further controlled clinical trials and meta-analysis are needed to guide clinicians in their search of effective pharmacological alternatives to antidepressants in PTSD.

Psychopharmacotherapy of posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is a psychiatric disorder that develops after a psychological trauma usually caused by a situation perceived as deeply threatening to a person's life or integrity. Complex neurobiological changes triggered by such a traumatic and stressful experience may explain a wide range of PTSD symptoms and provide the rationale for psychopharmacological treatment. Selective serotonin-reuptake inhibitors make the first-line treatment of PTSD. Clinical experience has shown that they are more effective than noradrenalin-reuptake inhibitors or tricyclic antidepressants. Antipsychotic drugs, especially atypical ones, have been shown effective in PTSD patients with psychotic characteristics or refractoriness to other treatments. Mood stabilizers seem to reduce mostly autonomous overreactions to stress, whereas the evidence for effectiveness of monoamine oxidase inhibitors is largely inconclusive. Other groups of medications, such as serotonin agonists and antagonists, new antidepressants, dual inhibitors of serotonin- and noradrenalin-reuptake, anticonvulsants, and opiate antagonists are also sometimes used in PTSD treatment. However, as shown in the present review, most clinical studies performed to date to investigate the effectiveness of different psychopharmacological agents in the therapy of PTSD have serious limitations in terms of small sample size, lack of blinding and randomization, and small effect size. More rigorously designed, comparative studies are needed to determine the usefulness, efficacy, tolerability, and safety of particular psychopharmaceutical drugs in the treatment of this therapeutically and functionally challenging disorder.

Comorbid anxiety in bipolar disorder alters treatment and prognosis

Mood disorders in general, and bipolar disorder in particular, are unique among the psychiatric conditions in that they are associated with extraordinarily high rates of comorbidity with a multitude of psychiatric and medical conditions. Among all the potential comorbidities, co-occurring anxiety disorders stand out due to their very high prevalence. Outcome in bipolar illness is worse in the presence of a comorbid anxiety disorder. The coexistence of an anxiety disorder presents a particularly difficult challenge in the treatment of bipolar illness since antidepressants, the mainstay of pharmacologic treatments for anxiety, may adversely alter the course of manic-depression. Identification of anxiety disorders in bipolar patients is important. The treatment plan needs to balance the potential benefit and harm of antidepressant administration.

Monoamine oxidase (MAO) intron 13 polymorphism and platelet MAO-B activity in combat-related posttraumatic stress disorder

BACKGROUND

The neurobiology of posttraumatic stress disorder (PTSD) involves alterations in multiple neuroendocrine and neurotransmitter systems. Platelet monoamine oxidase (MAO-B) has been associated with susceptibility to various psychiatric disorders, personality traits and behaviors.

METHODS

Platelet MAO-B activity and MAO-B intron 13 polymorphism (a G/A substitution) were determined in male war veterans (n=106) with DSM-IV diagnosed current and chronic PTSD, divided into subgroups of PTSD patients with (n=28) or without (n=78) psychotic features, combat exposed veterans (n=41) who did not develop PTSD, and healthy control men (n=242).

RESULTS

Two-way ANOVAs revealed a significant effect of diagnosis and smoking, a significant effect of smoking, no significant effect of genotype, and no significant interaction between genotype, smoking or diagnosis, on platelet MAO-B activity. One-way ANOVAs showed significantly lower platelet MAO-B activity in smokers than in nonsmokers. After controlling for smoking, veterans with psychotic PTSD had significantly higher platelet MAO-B activity than veterans with or without PTSD, or healthy subjects.

LIMITATIONS

The results were obtained on peripheral biochemical marker, i.e. platelet MAO activity.

CONCLUSIONS

The MAO-B intron 13 polymorphism was not functional, and did not affect platelet MAO-B activity. The allele frequencies of the MAO-B genotype were similarly distributed among healthy controls and veterans with or without PTSD and/or psychotic symptoms. The results suggest that platelet MAO-B activity, controlled for smoking status, might be used as a peripheral marker of the psychotic symptoms in PTSD.

The Management of Post Traumatic Stress Disorder (PTSD) in the Primary Care Setting

Recent geopolitical events, including the terrorist attacks on the United States on September 11, 2001, and ongoing military operations in Iraq, have raised awareness of the often severe psychological after-effects of these and other types of traumatic events. Post traumatic stress disorder (PTSD) represents the most severe of these sequelae. PTSD is an under-recognized and under-treated chronic anxiety disorder associated with significant psychosocial morbidity, substance abuse, and a number of other negative health outcomes. Fortunately, the biologic underpinnings of this complex disorder and new advances in treatment are being realized. Early detection by primary care providers and rapid initiation of treatment are the keys to successful management of the disorder.

Risperidone monotherapy for post-traumatic stress disorder related to sexual assault and domestic abuse in women

Post-traumatic stress disorder is a common, chronic, and often disabling mental illness. Selective serotonin reuptake inhibitors are the usual first-line treatment for post-traumatic stress disorder, but many patients fail to respond adequately. Thus, other treatment options, including the atypical antipsychotics such as risperidone, need to be tested. Women between the ages of 19 and 64 years with post-traumatic stress disorder were enrolled. Symptom severity was rated at baseline using the Treatment Outcomes Post-traumatic Stress Disorder Scale-8, Hamilton Rating Scale for Anxiety, Hamilton Rating Scale for Depression, and Clinician Administered Post-traumatic Stress Disorder Scale. After washout from other psychotropic medications, 20 participants were randomized to either risperidone or placebo. Total score on the Treatment Outcomes Post-traumatic Stress Disorder Scale-8 served as the primary outcome measure. Repeated-measures analysis of variance was followed by Newman-Keuls tests. A significant main effect exists for visits using the Treatment Outcomes Post-traumatic Stress Disorder Scale-8 raw score. For the treatment group, the difference between baseline Treatment Outcomes Post-traumatic Stress Disorder Scale-8 scores and treatment visit scores was significant beginning at visit 6 and continued through visit 11. No significant difference observed between baseline and any treatment visit for the placebo group. The Clinician Administered Post-traumatic Stress Disorder Scale, Hamilton Rating Scale for Anxiety, and Hamilton Rating Scale for Depression data revealed a similar pattern. In this small pilot study, risperidone monotherapy was more effective than placebo in the treatment of post-traumatic stress disorder.

Post-traumatic stress disorder: evidence-based research for the third millennium

The stress that results from traumatic events precipitates a spectrum of psycho-emotional and physiopathological outcomes. Post-traumatic stress disorder (PTSD) is a psychiatric disorder that results from the experience or witnessing of traumatic or life-threatening events. PTSD has profound psychobiological correlates, which can impair the person's daily life and be life threatening. In light of current events (e.g. extended combat, terrorism, exposure to certain environmental toxins), a sharp rise in patients with PTSD diagnosis is expected in the next decade. PTSD is a serious public health concern, which compels the search for novel paradigms and theoretical models to deepen the understanding of the condition and to develop new and improved modes of treatment intervention. We review the current knowledge of PTSD and introduce the role of allostasis as a new perspective in fundamental PTSD research. We discuss the domain of evidence-based research in medicine, particularly in the context of complementary medical intervention for patients with PTSD. We present arguments in support of the notion that the future of clinical and translational research in PTSD lies in the systematic evaluation of the research evidence in treatment intervention in order to insure the most effective and efficacious treatment for the benefit of the patient.

The role of glutamate in anxiety and related disorders

Anxiety, stress, and trauma-related disorders are a major public health concern in the United States. Drugs that target the gamma-aminobutyric acid or serotonergic system, such as benzodiazepines and selective serotonin reuptake inhibitors, respectively, are the most widely prescribed treatments for these disorders. However, the role of glutamate in anxiety disorders is becoming more recognized with the belief that drugs that modulate glutamatergic function through either ionotropic or metabotropic glutamate receptors have the potential to improve the current treatment of these severe and disabling illnesses. Animal models of fear and anxiety have provided a method to study the role of glutamate in anxiety. This research has demonstrated that drugs that alter glutamate transmission have potential anxiolytic action for many different paradigms including fear-potentiated startle, punished responding, and the elevated plus maze. Human clinical drug trials have demonstrated the efficacy of glutamatergic drugs for the treatment of obsessive-compulsive disorder, posttraumatic stress disorder, generalized anxiety disorder, and social phobia. Recent data from magnetic resonance imaging studies provide an additional link between the glutamate system and anxiety. Collectively, the data suggest that future studies on the mechanism of and clinical efficacy of glutamatergic agents in anxiety disorders are appropriately warranted.