Tryptophan overloading activates brain regions involved with cognition, mood and anxiety

ABSTRACT Tryptophan is the only precursor of serotonin and mediates serotonergic activity in the brain. Previous studies have shown that the administration of tryptophan or tryptophan depletion significantly alters cognition, mood and anxiety. Nevertheless, the neurobiological alterations that follow these changes have not yet been fully investigated. The aim of this study was to verify the effects of a tryptophan-enriched diet on immunoreactivity to Fos-protein in the rat brain. Sixteen male Wistar rats were distributed into two groups that either received standard chow diet or a tryptophan-enriched diet for a period of thirty days. On the morning of the 31st day, animals were euthanized and subsequently analyzed for Fos-immunoreactivity (Fos-ir) in the dorsal and median raphe nuclei and in regions that receive serotonin innervation from these two brain areas. Treatment with a tryptophan-enriched diet increased Fos-ir in the prefrontal cortex, nucleus accumbens, paraventricular hypothalamus, arcuate and ventromedial hypothalamus, dorsolateral and dorsomedial periaqueductal grey and dorsal and median raphe nucleus. These observations suggest that the physiological and behavioral alterations that follow the administration of tryptophan are associated with the activation of brain regions that regulate cognition and mood/anxiety-related responses.

Predictors of response in the treatment of moderate depression

Objective: To identify neurocognitive and sociodemographic variables that could be associated with clinical response to three modalities of treatment for depression, as well as variables that predicted superior response to one treatment over the others. Method: The present study derives from a research project in which depressed patients (n=272) received one of three treatments – long-term psychodynamic psychotherapy (n=90), fluoxetine therapy (n=91), or a combination thereof (n=91) – over a 24-month period. Results: Sociodemographic variables were not found to be predictive. Six predictive neurocognitive variables were identified: three prognostic variables related to working memory and abstract reasoning; one prescriptive variable related to working memory; and two variables found to be moderators. Conclusions: The results of this study indicate subgroups of patients who might benefit from specific therapeutic strategies and subgroups that seem to respond well to long-term psychodynamic psychotherapy and combined therapy. The moderators found suggest that abstract reasoning and processing speed may influence the magnitude and/or direction of clinical improvement.

Tolerability and effectiveness of fluoxetine, metformin and sibutramine in reducing anthropometric and metabolic parameters in obese patients / Tolerabilidade e eficácia da fluoxetina, metformina e sibutramina na redução de parâmetros antropométricos e metabólicos em pacientes obesos

The aim of this study is to assess the effects of sibutramine (S) 15 mg/day, fluoxetine (F) 60 mg/day, and metformin (M) 1,700 mg/day, as an adjunct therapy to a 1,500 kcal/day diet, in reducing anthropometric and metabolic parameters. S (n= 8), F (n= 9), and M (n= 8) were compared to placebo (n= 10) in 35 obese patients in a 90-day trial. Side effects were also studied during the treatment. The data demonstrated that F therapy resulted in a greater average reduction in BMI (11.0 percent), weight (10.0 percent), abdominal circumference (11.0 percent) and percentfatty-tissue (12.8). An elevation in HDL-cholesterol (25.8 percent) and a reduction in average triglyceride levels (28.3 percent) were also shown. S presented a 7.91 percent reduction in the abdominal circumference and a 9.65 reduction in percentfatty-tissue was also found. M group presented reductions in BMI (4.03 percent), waist circumference (6.92 percent), HOMA (23.5 percent) and blood pressure (6.08 percent in systolic and 2.08 percent in diastolic). In general, the three drugs can be considered well tolerated. We concluded that F and S demonstrated a greater mean reduction in anthropometric and metabolic parameters when compared to M, however all of them are useful for that purpose, when the subjectsÆ characteristics are considered.

O objetivo deste estudo foi avaliar o efeito da sibutramina (S) 15 mg/dia, fluoxetina (F) 60 mg/dia, e metformina (M) 1.700 mg/dia, associadas a uma dieta de 1.500 kcal/dia, na redução de parâmetros antropométricos e metabólicos. S (n= 8), F (n= 9) e M (n= 8) foram comparadas ao placebo (n= 10) em 35 pacientes obesos durante 90 dias de tratamento. As reações adversas também foram avaliadas durante o tratamento. O grupo F demonstrou uma redução no IMC (11,0 por cento), peso (10,0 por cento), circunferência abdominal (11,0 por cento) e por cento de tecido adiposo (12,8). Também foram observados um aumento nos níveis de HDL-colesterol (25,8 por cento) e uma redução nos níveis de triglicérides (28,3 por cento), no grupo F. O grupo S apresentou uma redução de 7,91 por cento na circunferência abdominal e de 9,65 na por cento de tecido adiposo. Já o grupo M apresentou reduções no IMC (4,03 por cento), circunferência abdominal (6,92 por cento), HOMA (23,5 por cento) e pressão arterial (6,08 por cento na sistólica, 2,08 por cento na diastólica). Os três fármacos analisados foram bem tolerados durante o tratamento. Concluímos que a F e a S demonstraram maior eficácia na redução dos parâmetros antropométricos e metabólicos dos pacientes obesos quando comparadas à M, entretanto todas podem ser prescritas para essa finalidade, desde que sejam consideradas as características individuais dos pacientes.

Escolha do tratamento da narcolepsia / The treatment of narcolepsy

O tratamento da narcolepsia visa seus dois sintomas principais, a sonolência excessiva diurna e a cataplexia. A primeira é usualmente controlada com anfetmina, metilfenidato e pemoline. Mais recentemente, inibidores da MAO, e principalmente os inibidores seletivos de MAO-A e B têm mostrado resultados promissores, com a selegilina. Modafinil, um estimulante alfa-1-adrenérgico tem também evidenciado bons resultados. A cataplexia, por sua vez, é geralmente tratada com antidepressivos tricíclicos. Dentre as novas drogas, sem efeito colateral antropínico, temos o hidrocloreto de viloxazina, um bloqueador de recaptaçäo da noradrenalina