The localization of substance P in brain regions that coordinate stress responses and receive convergent monoaminergic innervation suggested that substance P antagonists might have psychotherapeutic properties. Like clinically used antidepressant and anxiolytic drugs, substance P antagonists suppressed isolation-induced vocalizations in guinea pigs. In a placebo-controlled trial in patients with moderate to severe major depression, robust antidepressant effects of the substance P antagonist MK-869 were consistently observed. In preclinical studies, substance P antagonists did not interact with monoamine systems in the manner seen with established antidepressant drugs. These findings suggest that substance P may play an important role in psychiatric disorders.

The observed improvements in ADAS-Cog and CIBIC+ following treatment with xanomeline provide the first evidence, from a large-scale, placebo-controlled clinical trial, that a direct-acting muscarinic receptor agonist can improve cognitive function in patients with AD. Furthermore, the dramatic and favorable effects on disturbing behaviors in AD suggest a novel approach for treatment of noncognitive symptoms.

Many drugs have been associated with QTc prolongation and, in some cases, this is augmented by concomitant administration with metabolic inhibitors. The effects of 6 antipsychotics on the QTc interval at and around the time of estimated peak plasma/serum concentrations in the absence and presence of metabolic inhibition were characterized in a prospective, randomized study in which patients with psychotic disorders reached steady-state on either haloperidol 15 mg/d (n = 27), thioridazine 300 mg/d (n = 30), ziprasidone 160 mg/d (n = 31), quetiapine 750 mg/d (n = 27), olanzapine 20 mg/d (n = 24), or risperidone 6-8 mg/d increased to 16 mg/d (n = 25/20). Electrocardiograms (ECGs) were done at estimated Cmax at steady-state on both antipsychotic monotherapy and after concomitant administration of appropriate cytochrome P-450 (CYP450) inhibitor(s). Mean QTc intervals did not exceed 500 milliseconds in any patient taking any of the antipsychotics studied, in the absence or presence of metabolic inhibition. The mean QTc interval change was greatest in the thioridazine group, both in the presence and absence of metabolic inhibition. The presence of metabolic inhibition did not significantly augment QTc prolongation associated with any agent. Each of the antipsychotics studied was associated with measurable QTc prolongation at steady-state peak plasma concentrations, which was not augmented by metabolic inhibition. The theoretical risk of cardiotoxicity associated with QTc prolongation should be balanced against the substantial clinical benefits associated with atypical antipsychotics and the likelihood of other toxicities.

Context.-The serotonin reuptake inhibitors are the treatment of choice for patients with obsessive-compulsive disorder; however, empirical support for this assertion has been weaker for children and adolescents than for adults.Objective.-To evaluate the safety and efficacy of the selective serotonin reuptake inhibitor sertraline hydrochloride in children and adolescents with obsessivecompulsive disorder.Design.-Randomized, double-blind, placebo-controlled trial.Patients.-One hundred eighty-seven patients: 107 children aged 6 to 12 years and 80 adolescents aged 13 to 17 years randomized to receive either sertraline (53 children, 39 adolescents) or placebo (54 children, 41 adolescents).Setting.-Twelve US academic and community clinics with experience conducting randomized controlled trials.Intervention.-Sertraline hydrochloride was titrated to a maximum of 200 mg/d during the first 4 weeks of double-blind therapy, after which patients continued to receive this dosage of medication for 8 more weeks. Control patients received placebo.Main Outcome Measures.-The Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS), the National Institute of Mental Health Global Obsessive Compulsive Scale (NIMH GOCS), and the NIMH Clinical Global Impressions of Severity of Illness (CGI-S) and Improvement (CGI-I) rating scales.Results.-In intent-to-treat analyses, patients treated with sertraline showed significantly greater improvement than did placebo-treated patients on the CY-BOCS (adjusted mean, −6.8 vs −3.4, respectively; P = .005), the NIMH GOCS (−2.2 vs −1.3, respectively; P = .02), and the CGI-I (2.7 vs 3.3, respectively; P = .002) scales. Significant differences in efficacy between sertraline and placebo emerged at week 3 and persisted for the duration of the study. Based on CGI-I ratings at end point, 42% of patients receiving sertraline and 26% of patients receiving placebo were very much or much improved. Neither age nor sex predicted response to treatment. The incidence of insomnia, nausea, agitation, and tremor were significantly greater in patients receiving sertraline; 12 (13%) of 92 sertraline-treated patients and 3 (3.2%) of 95 placebo-treated patients discontinued prematurely because of adverse medical events (P = .02). No clinically meaningful abnormalities were apparent on vital sign determinations, laboratory findings, or electrocardiographic measurements.Conclusion.-Sertraline appears to be a safe and effective short-term treatment for children and adolescents with obsessive-compulsive disorder.

Cholinesterase (ChE) inhibition represents the most efficacious treatment approach for Alzheimer's disease (AD) to date. This multiple-dose study has examined the relationship between inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities in the cerebrospinal fluid (CSF) and cognitive change (measured by the Computerised Neuropsychological Test Battery [CNTB]) following administration of the ChE inhibitor, rivastigmine (Exelon). In 18 patients with mild to moderate AD, CNTB scores, activities of AChE and BuChE in the CSF, and plasma BuChE activity were determined prior to treatment with rivastigmine. Doses of rivastigmine were then titrated (1 mg b.i.d./week) to final doses of 1, 2, 3, 4, 5 or 6 mg b.i.d. (n = 3 per dose). Following treatment with the target dose of rivastigmine for at least 3 days, CNTB scores were re-determined. CSF samples were continuously collected together with plasma samples prior to and for 12 hours after the final dose of rivastigmine, and AChE and BuChE activities determined.AChE in CSF and BuChE in plasma were dose-dependently inhibited by rivastigmine treatment. The inhibition of BuChE in CSF was not clearly dose-dependent. A statistically significant correlation was observed between the change in CNTB summary score and inhibition of AChE activity (r = -0.56, p < 0.05) and BuChE activity (r = -0.65, p < 0.01) in CSF. Improvement in speed-, attention- and memory-related subtests of the CNTB correlated significantly with inhibition of BuChE but not AChE activity in CSF. Weak or absent correlation with change in cognitive performance was noted for inhibition of plasma BuChE. These results indicate that cognitive improvement with rivastigmine in AD is associated with central inhibition of ChEs and support a role for central BuChE in addition to AChE inhibition in modulating cholinergic function in AD.