FDA OKs New Kind of Sleep Drug Suvorexant (Belsomra)

0 15 diciembre, 2014

The US Food and Drug Administration (FDA) today approved a first-in-class insomnia drug called suvorexant (Belsomra, Merck) after the manufacturer lowered the dosages to satisfy the agency’s safety concerns. Merck announced that the FDA had declined to approve suvorexant until the starting dose for most patients was 10 mg. The agency also said that proposed upper-limit doses of 30 mg for elderly patients and 40 mg for nonelderly patients were unsafe. In a news release today, the FDA said it had approved suvorexant at 4 different strengths — 5 mg, 10 mg, 15 mg, and 20 mg. The total dosage in 1 day should not exceed 20 mg. Merck noted in its own news release today that the recommended dose is 10 mg for most patients, just as the FDA insisted. Suvorexant, an orexin receptor antagonist, is the first drug of its kind to be approved for patients with insomnia. It alters the signaling of orexins, neurotransmitters responsible for regulating the sleep-wake cycle. The FDA determined that suvorexant was effective based on 3 clinical trials involving more than 500 participants. Those receiving suvorexant nodded off more quickly and spent less time awake for the rest of the night compared with participants given a placebo. Drowsiness was the most commonly reported adverse event for clinical trial participants taking suvorexant, which is classified as a Sche

Posted in Psiquiatría y psicología by qubitoz
0 15 diciembre, 2014

Investigators at Dalhousie University in Halifax, Canada, found that CRP, an “easily accessible biomarker of systemic inflammation,” predicted response to the antidepressants escitalopram (Lexapro, Forest Laboratories, Inc) and nortriptyline. “While there have been other biomarkers identified [to predict response to antidepressants], CRP has the major advantage of being ‘differential’ ― it predicts response to one drug in one direction and response to an alternative drug in the opposite direction,” lead author Rudolf Uher, MD, PhD, told Medscape Medical News. Low CRP, Better Response . With previous evidence showing an association between systemic inflammation and depression, the researchers wanted to investigate the hypothesis that a similar relationship might exist between CRP and response to treatment for depression, using the 2 different antidepressants ― escitalopram, a selective serotonin reuptake inhibitor, and nortriptyline, a selective norepinephrine reuptake inhibitor. The study involved 241 adults with major depressive disorder who were enrolled in the Genome-Based Therapeutic Drugs for Depression (GENDEP) study, a multicenter, randomized clinical trial. Patients were randomly assigned to receive 12 weeks of treatment with escitalopram (N = 115) or nortriptyline (N = 126), and their CRP levels were measured at baseline. Patients wit

Posted in Psiquiatría y psicología by qubitoz
0 15 diciembre, 2014

Stimulation with a low-strength electromagnetic field device immediately improves mood in patients with major depressive disorder (MDD) and bipolar disorder (BPD), new research shows. Results from a randomized, double-blind, sham-controlled study are exciting, especially because the effects were so rapid, lead author Michael L. Rohan, PhD, a physicist at McLean Hospital and Harvard Medical School, Belmont, Massachusetts, told Medscape Medical News. The device holds “great potential” as a clinical tool for psychiatrists, Dr. Rohan added. The ability of the rapidly oscillating electromagnetic field, called low-field magnetic stimulation (LFMS), to improve mood was discovered “serendipitously” about a decade ago. Researchers who were carrying out experimental MRI scans to assess brain chemistry noticed changes in depressed bipolar patients. After further research, Dr. Rohan designed and built the portable tabletop device that is now being studied. It consists of a magnetic coil, an amplifier, a waveform generator, and a computer. The US Food and Drug Administration (FDA) has determined that the device carries a nonsignificant risk. Dr. Rohan described the LFMS device as being similar in size and shape to “an old-fashioned mailbox.” Patients lie on a bed with a padded headrest. The top of their head fits into the device, leaving the rest of the

Posted in Psiquiatría y psicología by qubitoz
0 15 diciembre, 2014

A simple test examining involuntary eye movements may provide an objective way to tell whether individuals have attention-deficit/hyperactive disorder (ADHD) and whether stimulant medication will be an effective treatment, new research suggests. Investigators from Tel Aviv University in Tel Hashomer, Israel, observed increased microsaccades and blink rates in adults with ADHD, which normalized with methylphenidate treatment.  “Striking” Predictive Effect “The rationale behind our study was following recent studies ― of ours and others ― which found that the rate of microsaccades is inversely correlated with the level of attention,” Dr. Fried told Medscape Medical News. In this latest study, the investigators recorded involuntary eye movements in 22 adults with ADHD with and without methylphenidate and 22 control individuals while they performed the test of variables of attention (TOVA). They found that unmedicated ADHD patients had significantly higher rates of eye blinks and microsaccades compared with control participants. This effect was largest in the peristimulus period, “where eye movements should be suppressed because they could interfere with the task,” the researchers write. In addition, stimulant medication had a “striking effect” on involuntary eye movements, with full normalization of the

Posted in Psiquiatría y psicología by qubitoz
0 15 diciembre, 2014

Alterations in a gene linked to stress reactions may eventually help clinicians identify patients at increased risk for suicidal behavior, including attempts, potentially by way of a simple blood test, new research shows. Investigators at the Johns Hopkins University School of Medicine in Baltimore, Maryland, examined postmortem brains and found a genetic and epigenetic link between suicide and the single- nucleotide polymorphism (SNP) rs7208505 “within the 3′ untranslated region of the SKA2 gene.” The investigators were able to then replicate this finding in 2 other postmortem brain cohorts and in blood draws from 3 live participant cohorts. They found a significantly lower SKA2 gene expression in those with suicidal behavior and an association with variations of rs7208505. A final analysis, this time of salivary cortisol, showed that SKA2 variations may modulate cortisol suppression. The study was published July 30 in the American Journal of Psychiatry.

Posted in Psiquiatría y psicología by qubitoz
0 15 diciembre, 2014

Although the risk of developing dementia doubles in older adults diagnosed with major depression vs those without the disorder, the mechanism is unclear. Most previous studies have examined 1 or 2 biomarkers when investigating this question. However, in the current study, the investigators tested 242 blood-based proteins and also examined structural brain abnormalities. A total of 80 adults with remitted late-life depression were enrolled; 36 had MCI (67% women; mean age, 73.4 years), and 44 had normal cognitive function (87% women; mean age, 72.4 years). Whole-blood samples were taken from all participants and tested for the proteins associated with pathways for cancer, cardiovascular disease, metabolic syndrome, psychiatric disorders, and neurodegenerative disorders.

In addition, positron emission tomography using Pittsburgh compound B (PiB-PET) was used to measure brain amyloid-beta (Aβ) deposition, thought to be involved in Alzheimer’s disease, and MRI scans were used to measure white matter hyperintensity and whole-brain gray matter atrophy volumes. Results showed that the participants who had both depression and MCI had significant “differential expression” of 24 proteins used in the regulation of immune-inflammatory activity (including higher levels of CCL13-MCP-4 and CXCL11-interferon-inducible T-

Posted in Psiquiatría y psicología by qubitoz
0 15 diciembre, 2014

Investigadores estadounidenses han encontrado evidencias que el tratamiento diario con sulforafano puede mejorar algunos síntomas de los trastornos del espectro autista (TEA). El compuesto, que se halla en alimentos como el brócoli, la coliflor y la col, logró una mejora significativa en los pacientes.

El estudio, aleatorizado y doble ciego, se basó en la experiencia con 44 pacientes de 13-27 años que habían sido diagnosticados de TEA moderado a grave. Durante 18 semanas, un grupo de 29 pacientes recibió una dosis diaria de 50-150 µmol de sulforafano –derivado de extracto de brotes de brócoli–, y a los 15 restantes se les administró un placebo. Tras cuatro semanas sin tratamiento, se sometieron a tres evaluaciones del comportamiento: Aberrant Behavior Checklist, Social Responsiveness Scale y Clinical Global Impression Improvement Scale.

Las puntuaciones medias de cada una de las evaluaciones fueron significativamente mejores en quienes recibieron sulforafano en comparación con el grupo placebo. Así, se apreciaba una mejoría en el comportamiento y, para el final del estudio, tanto los médicos como los cuidadores o los miembros de la familia sabían perfectamente quién había recibido el fármaco debido a sus cambios en el comp

Posted in Psiquiatría y psicología by qubitoz
0 15 diciembre, 2014

Un nuevo estudio en ratones muestra cómo el ejercicio físico induce cambios en el músculo esquelético, los cuales ocasionan la limpieza de una sustancia que se acumula en la sangre durante los momentos de estrés y que es perjudicial para el cerebro. Esto explicaría los cambios bioquímicos que protegen al cerebro del estrés gracias al ejercicio físico.

Anteriores investigaciones ya mostraron que la proteína PGC-1α1 se incrementa en el músculo cuando se realiza ejercicio. En este trabajo, los investigadores utilizaron ratones genéticamente modificados con altos niveles de PGC-1α1 en el músculo esquelético, que desarrollaron músculos bien entrenados (incluso sin ejercicio).

Tanto estos ratones como los que no fueron modificados con la proteína fueron expuestos a un ambiente estresante, como ruidos altos, luces intermitentes y alteraciones en el ritmo circadiano. Tras cinco semanas, los ratones sin tratar mostraron un comportamiento depresivo, mientras que los ratones genéticamente modificados no presentaban dichos síntomas. 

La hipótesis inicial era que los músculos entrenados podrían producir una sustancia con efectos beneficiosos para el cerebro. Ahora sucedería lo contrario: los músculos bien entr

Posted in Psiquiatría y psicología by qubitoz
0 12 diciembre, 2014

Hacia los 40 años, casi la totalidad de individuos con síndrome de Down desarrollan los cambios cerebrales asociados con la enfermedad Alzheimer (EA), hasta el punto que a los 65 años, un 75% de ellos muestra señales de demencia. Por ello, una investigación ha pretendido averiguar cómo la copia extra del cromosoma 21 y sus genes provocan que las personas con síndrome de Down tengan un riesgo mucho mayor de desarrollar la demencia típica de la EA.

Los resultados revelan que, en el cerebro de las personas con síndrome de Down y EA, la proteína SNX27 regula la generación de proteína β-amiloide. SNX27 reduce la generación de β-amiloide a través de interacciones con la γ-secretasa, un enzima que fragmenta la proteína precursora de la β-amiloide. Cuando SNX27 interactúa con la γ-secretasa, este enzima se desactiva y no puede producir β-amiloide. Niveles más bajos de SNX27 llevan a niveles superiores de γ-secretasa funcional, que a su vez conducen a niveles mayores de β-amiloide.

Los investigadores abordaron la cuestión de cómo niveles más bajos de SNX27 en el síndrome de Down son el resultado de una copia extra de una molécula de ARN codificada por el cromosoma 21, denominada miRNA-155. La copia extra del cromosoma 21 produce niveles elevado

Posted in Psiquiatría y psicología by qubitoz
0 12 diciembre, 2014

A single brain protein appears to mediate resilience to stress and susceptibility to depression, US scientists have discovered in findings that may offer targets for novel and more effective antidepressants.

The researchers found that beta-catenin activity in D2-type dopamine receptor neurons in the nucleus accumbens plays a central role in the ability to deal with stress and be resilient to depression. Moreover, activity is reduced in the brains of depressed patients.

The research was published online November 12 in Nature.

“We got keyed in on this gene because earlier genome-wide data in animals and humans suggested that beta-catenin signaling might be altered in the nucleus accumbens,” Eric J. Nestler, MD, PhD, Nash Family Professor, chair of the Department of Neuroscience, and director of the Friedman Brain Institute at the Icahn School of Medicine at Mount Sinai in New York City, told Medscape Medical News.

“So we started out by verifying whether that was true.”

In a mouse model, the team demonstrated that contro

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