Onset of Alzheimer disease in apolipoprotein ɛ4 carriers is earlier in butyrylcholinesterase K variant carriers.

BACKGROUND: The authors sought to examine the impact of the K-variant of butyrylcholinesterase (BCHE-K) carrier status on age-at-diagnosis of Alzheimer disease (AD) in APOE4 carriers. METHODS: Patients aged 50-74 years with cerebrospinal fluid (CSF) biomarker-confirmed AD, were recruited to clinical trial (NCT03186989 since June 14, 2017). Baseline demographics, disease characteristics, and biomarkers were evaluated in 45 patients according to BCHE-K and APOE4 allelic status in this post-hoc study. RESULTS: In APOE4 carriers (N = 33), the mean age-at-diagnosis of AD in BCHE-K carriers (n = 11) was 6.4 years earlier than in BCHE-K noncarriers (n = 22, P < .001, ANOVA). In APOE4 noncarriers (N = 12) there was no observed influence of BCHE-K. APOE4 carriers with BCHE-K also exhibited slightly higher amyloid and tau accumulations compared to BCHE-K noncarriers. A predominantly amyloid, limited tau, and limbic-amnestic phenotype was exemplified by APOE4 homozygotes with BCHE-K. In the overall population, multiple regression analyses demonstrated an association of amyloid accumulation with APOE4 carrier status (P < .029), larger total brain ventricle volume (P < .021), less synaptic injury (Ng, P < .001), and less tau pathophysiology (p-tau181, P < .005). In contrast, tau pathophysiology was associated with more neuroaxonal damage (NfL, P = .002), more synaptic injury (Ng, P < .001), and higher levels of glial activation (YKL-40, P = .01). CONCLUSION: These findings have implications for the genetic architecture of prognosis in early AD, not the genetics of susceptibility to AD. In patients with early AD aged less than 75 years, the mean age-at-diagnosis of AD in APOE4 carriers was reduced by over 6 years in BCHE-K carriers versus noncarriers. The functional status of glia may explain many of the effects of APOE4 and BCHE-K on the early AD phenotype. TRIAL REGISTRATION: NCT03186989 since June 14, 2017.

Tau-targeting antisense oligonucleotide MAPTRx in mild Alzheimer's disease: a phase 1b, randomized, placebo-controlled trial.

Tau plays a key role in Alzheimer's disease (AD) pathophysiology, and accumulating evidence suggests that lowering tau may reduce this pathology. We sought to inhibit MAPT expression with a tau-targeting antisense oligonucleotide (MAPTRx) and reduce tau levels in patients with mild AD. A randomized, double-blind, placebo-controlled, multiple-ascending dose phase 1b trial evaluated the safety, pharmacokinetics and target engagement of MAPTRx. Four ascending dose cohorts were enrolled sequentially and randomized 3:1 to intrathecal bolus administrations of MAPTRx or placebo every 4 or 12 weeks during the 13-week treatment period, followed by a 23 week post-treatment period. The primary endpoint was safety. The secondary endpoint was MAPTRx pharmacokinetics in cerebrospinal fluid (CSF). The prespecified key exploratory outcome was CSF total-tau protein concentration. Forty-six patients enrolled in the trial, of whom 34 were randomized to MAPTRx and 12 to placebo. Adverse events were reported in 94% of MAPTRx-treated patients and 75% of placebo-treated patients; all were mild or moderate. No serious adverse events were reported in MAPTRx-treated patients. Dose-dependent reduction in the CSF total-tau concentration was observed with greater than 50% mean reduction from baseline at 24 weeks post-last dose in the 60 mg (four doses) and 115 mg (two doses) MAPTRx groups. Clinicaltrials.gov registration number: NCT03186989 .

Targeting Huntingtin Expression in Patients with Huntington's Disease.

BACKGROUND: Huntington's disease is an autosomal-dominant neurodegenerative disease caused by CAG trinucleotide repeat expansion in HTT, resulting in a mutant huntingtin protein. IONIS-HTTRx (hereafter, HTTRx) is an antisense oligonucleotide designed to inhibit HTT messenger RNA and thereby reduce concentrations of mutant huntingtin. METHODS: We conducted a randomized, double-blind, multiple-ascending-dose, phase 1-2a trial involving adults with early Huntington's disease. Patients were randomly assigned in a 3:1 ratio to receive HTTRx or placebo as a bolus intrathecal administration every 4 weeks for four doses. Dose selection was guided by a preclinical model in mice and nonhuman primates that related dose level to reduction in the concentration of huntingtin. The primary end point was safety. The secondary end point was HTTRx pharmacokinetics in cerebrospinal fluid (CSF). Prespecified exploratory end points included the concentration of mutant huntingtin in CSF. RESULTS: Of the 46 patients who were enrolled in the trial, 34 were randomly assigned to receive HTTRx (at ascending dose levels of 10 to 120 mg) and 12 were randomly assigned to receive placebo. Each patient received all four doses and completed the trial. Adverse events, all of grade 1 or 2, were reported in 98% of the patients. No serious adverse events were seen in HTTRx-treated patients. There were no clinically relevant adverse changes in laboratory variables. Predose (trough) concentrations of HTTRx in CSF showed dose dependence up to doses of 60 mg. HTTRx treatment resulted in a dose-dependent reduction in the concentration of mutant huntingtin in CSF (mean percentage change from baseline, 10% in the placebo group and -20%, -25%, -28%, -42%, and -38% in the HTTRx 10-mg, 30-mg, 60-mg, 90-mg, and 120-mg dose groups, respectively). CONCLUSIONS: Intrathecal administration of HTTRx to patients with early Huntington's disease was not accompanied by serious adverse events. We observed dose-dependent reductions in concentrations of mutant huntingtin. (Funded by Ionis Pharmaceuticals and F. Hoffmann-La Roche; ClinicalTrials.gov number, NCT02519036.).

Translating Antisense Technology into a Treatment for Huntington's Disease.

Advances in molecular biology and genetics have been used to elucidate the fundamental genetic mechanisms underlying central nervous system (CNS) diseases, yet disease-modifying therapies are currently unavailable for most CNS conditions. Antisense oligonucleotides (ASOs) are synthetic single stranded chains of nucleic acids that bind to a specific sequence on ribonucleic acid (RNA) and regulate posttranscriptional gene expression. Decreased gene expression with ASOs might be able to reduce production of the disease-causing protein underlying dominantly inherited neurodegenerative disorders. Huntington's disease (HD), which is caused by a CAG repeat expansion in exon 1 of the huntingtin (HTT) gene and leads to the pathogenic expansion of a polyglutamine (PolyQ ) tract in the N terminus of the huntingtin protein (Htt), is a prime candidate for ASO therapy.State-of-the art translational science techniques can be applied to the development of an ASO targeting HTT RNA, allowing for a data-driven, stepwise progression through the drug development process. A deep and wide-ranging understanding of the basic, preclinical, clinical, and epidemiologic components of drug development will improve the likelihood of success. This includes characterizing the natural history of the disease, including evolution of biomarkers indexing the underlying pathology; using predictive preclinical models to assess the putative gain-of-function of mutant Htt protein and any loss-of-function of the wild-type protein; characterizing toxicokinetic and pharmacodynamic effects of ASOs in predictive animal models; developing sensitive and reliable biomarkers to monitor target engagement and effects on pathology that translate from animal models to patients with HD; establishing a drug delivery method that ensures reliable distribution to relevant CNS tissue; and designing clinical trials that move expeditiously from proof of concept to proof of efficacy. This review focuses on the translational science techniques that allow for efficient and informed development of an ASO for the treatment of HD.

Understanding the beneficial and detrimental effects of donepezil and rivastigmine to improve their therapeutic value.

Cholinesterase enzymes metabolize acetylcholine (ACh). Inhibition of acetylcholinesterase (AChE) in damaged but functional cholinergic synapses in the brains of dementia patients increases intrasynaptic ACh. This enhances cholinergic neurotransmission and improves cognition. There is a window of opportunity for this symptomatic treatment effect that opens and closes during the course of dementia depending on when significant synaptic damage occurs. Cholinesterases also metabolize extrasynaptic ACh with butyrylcholinesterase (BuChE) apparently playing the major dynamic role in extracellular ACh homeostasis. Extracellular ACh plays a key regulatory role in controlling the reactivity and functional states of non-excitable cells, such as neuroglia. Current inhibitors of cholinesterases (ChEIs) have similar effects on intrasynaptic ACh, but differ markedly in abilities to upregulate extracellular AChE, inhibit BuChE, and influence the fibrilization of amyloid-ß peptides. Importantly, ChEIs can have detrimental disease modifying effects in particular individuals characterized by age, gender, and genotype. In contrast, preliminary evidence suggests that the right dose of the right ChEI in the right patient might significantly slow the progression of neurodegenerative processes. For a particular patient, understanding the condition of cholinergic synapses and the reactivity and functional status of neuroglia could allow administration of appropriate ChEI therapy for symptomatic and disease modifying benefits.

Antidepressant drug development: Focus on triple monoamine reuptake inhibition.

Many patients with major depressive disorder (MDD) only partially respond, and some have no clinically meaningful response, to current widely used antidepressant drugs. Due to the purported role of dopamine in the pathophysiology of depression, triple-reuptake inhibitors (TRIs) that simultaneously inhibit serotonin (5-HT), norepinephrine (NE) and dopamine reuptake could be a useful addition to the armamentarium of treatments for MDD. A TRI should more effectively activate mesolimbic dopamine-related reward-networks, restore positive mood and reduce potent 5-HT reuptake blockade associated "hypodopaminergic" adverse effects of decreased libido, weight gain and "blunting" of emotions. On the other hand, dopaminergic effects raise concern over abuse liability and TRIs may have many of the cardiovascular effects associated with NET inhibition. Several clinical development programs for potential TRI antidepressants have failed to demonstrate significantly greater efficacy than placebo or standard of care. Successful late-stage clinical development of a TRI is more likely if experimental research studies in the target population of depressed patients have demonstrated target engagement that differentially and dose-dependently improves assessments of reward-network dysfunction relative to existing antidepressants. TRI treatment could be individualized on the basis of predictive markers such as the burden of decreased positive mood symptoms and/or neuroimaging evidence of reward network dysfunction. This review focuses on how the next generation of monoamine-based treatments could be efficiently developed to address unmet medical need in MDD.

Restoration of positive mood states in major depression as a potential drug development target.

Restoration of positive mood, in addition to reducing negative mood, is an important treatment goal in the management of depression. The need to restore positive mood states in depressed patients is not adequately addressed by available treatments for major depressive disorder (MDD), suggesting that this mood dimension could be a useful target for drug development. However, for positive mood restoration to become a valid target for antidepressant drug development certain questions should be answered: are symptoms of decreased positive mood phenomenologically distinct from other symptoms of MDD? Should they be considered a distinct aspect of MDD in the diagnostic nomenclature? Is there evidence for differential responsiveness to treatment? Is the underlying pathophysiology understood and different from that of other MDD symptoms? Is low positive mood specific to depression or does it contribute to psychopathology in other disorders? Beyond these basic questions, this review identifies a number of design issues that need to be considered when conducting studies that target improving positive mood. These design issues include (1) what population to study, (2) what line of treatment to target, (3) the appropriateness and validation of methods and measures to evaluate positive mood and its restoration, (4) the role of functional outcome measures in determining success of the treatment, and (5) optimal designs for add-on therapy versus monotherapy agents.

Butyrylcholinesterase genotype and gender influence Alzheimer's disease phenotype.

Retrospective data are presented to support a spectrum of early Alzheimer's disease (AD) along a continuum defined by gender and genotype. The putative neurodegenerative mechanisms driving distinct phenotypes at each end of the spectrum are glial hypoactivity associated with early failure of synaptic cholinergic neurotransmission and glial overactivation associated with loss of neural network connectivity due to accelerated age-related breakdown of myelin. In early AD, male butyrylcholinesterase K-variant carriers with one or two apolipoprotein ɛ4 alleles have prominent medial temporal atrophy, synaptic failure, cognitive decline, and accumulation of aggregated beta-amyloid peptide. Increasing synaptic acetylcholine in damaged but still functional cholinergic synapses improves cognitive symptoms, whereas increasing the ability of glia to support synapses and to clear beta-amyloid peptide might be disease-modifying. Conversely, chronic glial overactivation can also drive degenerative processes and in butyrylcholinesterase K-variant negative females generalized glial overactivation may be the main driver from mild cognitive impairment to AD. Females are more likely than males to have accelerated age-related myelin breakdown, more widespread white matter loss, loss of neural network connectivity, whole brain atrophy, and functional decline. Increasing extracellular acetylcholine levels blocks glial activation, reduces myelin loss and damage to neural network connectivity, and is disease-modifying. Between extremes characterized by gender, genotype, and age, pathophysiology may be mixed and this spectrum may explain much of the heterogeneity of amnestic mild cognitive impairment. Preservation of the functional integrity of the neural network may be an important component of strengthening cognitive reserve and significantly delaying the onset and progression of dementia, particularly in females. Prospective confirmation of these hypotheses is required. Implications for future research and therapeutic opportunities are discussed.

Evaluation of dementia rating scales in Parkinson's disease dementia.

Disease-specific assessments are not currently available for patients with Parkinson's disease dementia (PDD). This study evaluated the criterion-related validity and test-retest reliability of the Alzheimer's Disease Assessment scale cognitive subscale (ADAS-cog) in terms of sensitivity for differentiation between mild and moderate severity impairment in PDD. Six other dementia rating scales and cognitive tests were also examined. A total of 113 patients with PDD or Alzheimer disease were recruited into this 4-week, multicenter study, segregated into 2 severity groups based on Mini-Mental State Examination (MMSE) score. Mean ADAS-cog scores showed a statistically significant separation between mild and moderate severity patients in both dementias (P < .001). For the ADAS-cog, test-retest Spearman correlation coefficients were significant for each dementia type and severity. This study demonstrated the criterion-related validity and test-retest reliability for ADAS-cog in patients with PDD and strong correlations with MMSE. This supports the validity of previous results obtained with these measures in studies of patients with PDD.

Emerging hypotheses regarding the influences of butyrylcholinesterase-K variant, APOE epsilon 4, and hyperhomocysteinemia in neurodegenerative dementias.

Non-enzymatic functions of butyrylcholinesterase (BuChE) include prevention of the aggregation of amyloid-beta peptide (A beta) in a concentration-dependent manner. This is mediated by the C-terminus of the protein, distal from the enzymatic site. The BuChE-K variant polymorphism lowers expression of BuChE protein and/or alters C-terminal activity. In combination with factors that increase production or reduce elimination of A beta, and/or increase susceptibility to A beta toxicity - such as the apolipoprotein E (APOE) epsilon 4 allele and/or hyperhomocysteinemia - BuChE-K may accelerate cholinergic synaptic and neuronal damage and cognitive decline. A beta-mediated damage to ascending cholinergic pathways may be further accentuated by Lewy body and/or cerebrovascular disease. As the disease advances and functioning cholinergic synapses disappear, both the rapid cognitive decline and response to cholinesterase inhibitor therapy in individuals with these factors may diminish. Non-enzymatic functions of the BuChE protein, APOE epsilon 4 status and hyperhomocysteinemia influence the progression of pathology, symptom expression, and response to cholinesterase inhibition in a stage-specific manner in neurodegenerative disorders associated with Alzheimer, Lewy body and vascular pathology.

Rivastigmine versus placebo in hyperhomocysteinemic Parkinson's disease dementia patients.

The effects of rivastigmine versus placebo in Parkinson's disease dementia (PDD) patients with elevated or normal/low plasma homocysteine were determined. In this prospective analysis of a 24-week, randomly assigned, placebo-controlled study of rivastigmine in PDD, subpopulations comprised patients with plasma homocysteine >or=14 micromol/L (elevated) or <14 micromol/L (normal/low). Coprimary outcomes were the Alzheimer's Disease Assessment Scale-cognitive subscale (ADAS-cog) and Alzheimer Disease Cooperative Society-Clinical Global Impression of Change (ADCS-CGIC). Secondary outcomes included additional measures of cognition, including attention and executive function, daily function, and neuropsychiatric symptoms. Adverse events (AEs) were monitored. In total, 342 of 541 patients provided samples for analysis, from which 72% had elevated plasma homocysteine. Hyperhomocysteinemic patients showed treatment differences (rivastigmine vs. placebo) of 4.0 on ADAS-cog and 0.7 on ADCS-CGIC (both P < 0.01), and significant treatment differences on secondary outcomes. Rivastigmine- and placebo-treated hyperhomocysteinemic patients (16.5% and 14.6%) discontinued the study because of AEs. Patients with normal/low homocysteine showed no treatment differences on primary or secondary outcomes (1.4 on the ADAS-cog and 0.1 on ADCS-CGIC, both P = ns); 16.7% and 10.3% rivastigmine- and placebo-treated patients discontinued because of AEs. Elevated homocysteine was associated with greater rivastigmine treatment differences than normal/low homocysteine.

Rivastigmine in dementia associated with Parkinson's disease and Alzheimer's disease: similarities and differences.

Parkinson's disease dementia (PDD) and Alzheimer's disease (AD) are both characterized by cognitive abnormalities, neuropsychiatric symptoms, and cholinergic deficits. We reviewed data from large, placebo-controlled clinical trials conducted with rivastigmine in patients with PDD and AD to evaluate similarities and differences in response to treatment. In placebo groups, AD patients appeared to show more rapid cognitive decline than those with PDD. Treatment effects (rivastigmine versus placebo) on cognitive performance over 6 months were quantitatively similar in both populations, but qualitatively different: in AD, cognitive abilities were stabilized by rivastigmine compared to declines in placebo groups, whereas in PDD symptomatic improvements above baseline drove treatment effects while placebo patients had limited change. On activities of daily living, stabilization (rather than improvement) was observed in both dementia types. A more aggressive course of placebo decline, and greater treatment differences (rivastigmine versus placebo), were seen in sub-populations of both PDD and AD patients with hallucinations at baseline. The safety and adverse event profiles were comparable in the two populations. In conclusion, the magnitude of effect with rivastigmine versus placebo is quantitatively comparable in patients with AD and PD, but the treatment effect tended to be one of stabilization in AD, while in PDD improvements over baseline were seen. In both populations, hallucinations may identify patients who are likely to be more treatment-responsive.

Targeting acetylcholinesterase and butyrylcholinesterase in dementia.

The cholinesterase inhibitors (ChE-Is) attenuate the cholinergic deficit underlying the cognitive and neuropsychiatric dysfunctions in patients with AD. Inhibition of brain acetylcholinesterase (AChE) has been the major therapeutic target of ChE-I treatment strategies for Alzheimer's disease (AD). AChE-positive neurons project diffusely to the cortex, modulating cortical processing and responses to new and relevant stimuli. Butyrylcholinesterase (BuChE)-positive neurons project specifically to the frontal cortex, and may have roles in attention, executive function, emotional memory and behaviour. Furthermore, BuChE activity progressively increases as the severity of dementia advances, while AChE activity declines. Therefore, inhibition of BuChE may provide additional benefits. The two cholinesterase (ChE) enzymes that metabolize acetylcholine (ACh) differ significantly in substrate specificity, enzyme kinetics, expression and activity in different brain regions, and complexity of gene regulation. In addition, recent evidence suggests that AChE and BuChE may have roles beyond 'classical' co-regulatory esterase functions in terminating ACh-mediated neurotransmission. 'Non-classical' roles in modulating the activity of other proteins, regional cerebral blood flow, tau phosphorylation, and the amyloid cascade may affect rates of AD progression. If these additional mechanisms are demonstrated to underlie clinically meaningful effects, modification of the over-simplistic cholinergic hypothesis in AD that is limited to symptomatic treatment, ignoring the potential of cholinergic therapies to modify the disease process, may be appropriate. The specificity of ChE inhibitory activity, up-regulation of AChE activity and changes in the composition of AChE molecular forms over time, selectivity for AD-relevant ChE molecular forms, brain vs. peripheral selectivity, and pharmacokinetic profile may be important determinants of the acute and long-term efficacy, safety and tolerability profiles of the different ChE-Is. This review focuses on new evidence for the roles of BuChE and AChE in symptom generation and rate of underlying disease progression in dementia, and argues that it may be appropriate to re-evaluate the place of ChE-Is in the treatment of dementia.

Lipid homeostasis and apolipoprotein E in the development and progression of Alzheimer's disease.

Extracellular amyloid plaques, intracellular neurofibrillary tangles, and loss of basal forebrain cholinergic neurons in the brains of Alzheimer's disease (AD) patients may be the end result of abnormalities in lipid metabolism and peroxidation that may be caused, or exacerbated, by beta-amyloid peptide (Abeta). Apolipoprotein E (apoE) is a major apolipoprotein in the brain, mediating the transport and clearance of lipids and Abeta. ApoE-dependent dendritic and synaptic regeneration may be less efficient with apoE4, and this may result in, or unmask, age-related neurodegenerative changes. The increased risk of AD associated with apoE4 may be modulated by diet, vascular risk factors, and genetic polymorphisms that affect the function of other transporter proteins and enzymes involved in brain lipid homeostasis. Diet and apoE lipoproteins influence membrane lipid raft composition and the properties of enzymes, transporter proteins, and receptors mediating Abeta production and degradation, tau phosphorylation, glutamate and glucose uptake, and neuronal signal transduction. The level and isoform of apoE may influence whether Abeta is likely to be metabolized or deposited. This review examines the current evidence for diet, lipid homeostasis, and apoE in the pathogenesis of AD. Effects on the cholinergic system and response to cholinesterase inhibitors by APOE allele carrier status are discussed briefly.

Acetylcholinesterase and its inhibition in Alzheimer disease.

Until recently, the only established function of acetylcholinesterase (AChE) was the termination of cholinergic neurotransmission. Therefore, the use of AChE inhibitors to treat symptoms caused by cholinergic imbalances in Alzheimer disease (AD) represented a rational approach. However, it is now clear that AChE and the cholinergic system may have broader effects in AD. Of particular interest may be signal transduction pathways mediated through cholinergic receptors that promote nonamyloidogenic amyloid precursor protein processing and decrease tau phosphorylation, and the role of AChE in the aggregation of beta-amyloid (Abeta) peptide. In addition, the neuronal and nonneuronal cholinergic systems have important roles in the modulation of regional cerebral blood flow. These findings may modify the overly simplistic cholinergic hypothesis in AD that is limited to symptomatic treatment and ignores the potential of cholinergic therapies as disease-modifying agents. Chronic increases in AChE activity may exacerbate neurodegenerative processes, make clinically relevant levels of AChE inhibition more difficult to achieve, and cause the therapeutic value of cholinesterase inhibitors (ChE-Is) to be limited and temporary. Rapidly reversible ChE-Is appear to increase AChE activity over the longer term whereas, remarkably, irreversible or very slowly reversible ChE-Is do not seem to have this effect. If such differences between ChE-Is are shown to have clinical correlates, this may prompt reconsideration of the rationale and expectations of some agents in the long-term management of AD.

A placebo-controlled study of sertraline in the treatment of outpatients with seasonal affective disorder.

RATIONALE: Seasonal affective disorder (SAD) is a relatively common cyclical depressive illness characterized by seasonal depressions during winter. The disorder is commonly responsive to light therapy, but antidepressant drug efficacy has not been definitely established. Serotonin selective re-uptake inhibitors are potentially efficacious treatments for SAD. OBJECTIVES: The objective of this study was to evaluate the efficacy, tolerability and safety of sertraline treatment for SAD. METHODS: One hundred and eighty seven outpatients with seasonal pattern recurrent winter depression (DSM-III-R defined) and a minimum 29-item Hamilton depression scale (SIGH-SAD version) score of 22 were randomized to 8 weeks treatment with either sertraline or placebo in a double-blind, multi-country, multi-center, parallel-group, flexible dose (50-200 mg once daily) study. Efficacy was investigated using physician and patient-rated scales measuring depression, anxiety and symptoms characteristic of seasonal affective disorder. RESULTS: Sertraline produced a significantly greater response than placebo at endpoint as measured by changes in the 29-item and 21-item Hamilton depression scales, the clinical global impression (CGI) severity scale, the Hamilton anxiety scale, and the hospital anxiety and depression scale. The proportion of sertraline-treated subjects achieving a response on the CGI improvement rating (ratings of 1 or 2) at endpoint (last observation carried forward) was significantly greater than that of the placebo group. Overall sertraline was well tolerated with the most frequent placebo adjusted adverse events, being nausea, diarrhea, insomnia and dry mouth. Adverse events were mostly mild to moderate and transient. CONCLUSIONS: Sertraline pharmacotherapy has been demonstrated to be an effective and well-tolerated therapy for out patients with SAD. As such, sertraline offers an important pharmacological option in the clinical management of this condition.

Double-blind placebo-controlled pilot study of sertraline in military veterans with posttraumatic stress disorder.

The efficacy of sertraline in the treatment of civilian posttraumatic stress disorder (PTSD) has been established by two large placebo-controlled trials. The purpose of the current pilot study was to obtain preliminary evidence of the efficacy of sertraline in military veterans suffering from PTSD. Outpatient Israeli military veterans with a DSM-III-R diagnosis of PTSD were randomized to 10 weeks of double-blind treatment with sertraline (50-200 mg/day; N = 23, 83% male, mean age = 41 years) or placebo (N = 19, 95% male, mean age = 38 years). Efficacy was evaluated by the Clinician-Administered PTSD Scale (CAPS-2) and by Clinical Global Impression Scale-Severity (CGI-S) and -Improvement (CGI-I) ratings. Consensus responder criteria consisted of a 30% or greater reduction in the CAPS-2 total severity score and a CGI-I rating of "much" or "very much" improved. The baseline CAPS-2 total severity score was 94.3 +/- 12.9 for sertraline patients, which is notably higher than that reported for most studies of civilian PTSD. On an intent-to-treat endpoint analysis, sertraline showed a numeric but not statistically significant advantage compared with placebo on the CAPS-2 total severity and symptom cluster scores. In the study completer analysis, the mean CGI-I score was 2.4 +/- 0.3 for sertraline and 3.4 +/- 0.3 for placebo (t = 2.55, df = 30, p = 0.016), CGI-I responder rates were 53% for sertraline and 20% for placebo (chi2 = 3.62, df = 1, p = 0.057), and combined CGI-I and CAPS-2 responder rates (>or=30% reduction in baseline CAPS-2 score) were 41% for sertraline and 20% for placebo (chi2 = 1.39, df = 1, p = 0.238). Sertraline treatment was well tolerated, with a 13% discontinuation rate as a result of adverse events. This pilot study suggests that sertraline may be an effective treatment in patients with predominantly combat-induced PTSD, although the effect size seems to be somewhat smaller than what has been reported in civilian PTSD studies. Adequately powered studies are needed to confirm these results and to assess whether continued treatment maintains or further improves response.