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People often rely on intuitive judgments at the expense of deliberate reasoning, but what determines the dominance of intuition over deliberation is not well understood. Here, we employed a psychopharmacological approach to unravel the role of two major endocrine stress mediators, cortisol and noradrenaline, in cognitive reasoning. Healthy participants received placebo, cortisol (hydrocortisone) and/or yohimbine, a drug that increases noradrenergic stimulation, before performing the cognitive reflection test (CRT). We found that cortisol impaired performance in the CRT by biasing responses toward intuitive, but incorrect answers. Elevated stimulation of the noradrenergic system, however, had no effect. We interpret our results in the context of the dual systems theory of judgment and decision making. We propose that cortisol causes a shift from deliberate, reflective cognition toward automatic, reflexive information processing., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Modafinil, a putative cognitive enhancing drug, has previously been shown to improve performance of healthy volunteers as well as patients with attention deficit disorder and schizophrenia, mainly in tests of executive functions. The aim of this study was to investigate the effects of modafinil on non-verbal cognitive functions in healthy volunteers, with a particular focus on variations of cognitive load, measures of motivational factors and the effects on creative problem-solving., Methods: A double-blind placebo-controlled parallel design study evaluated the effect of 200 mg of modafinil (N = 32) or placebo (N = 32) in non-sleep deprived healthy volunteers. Non-verbal tests of divergent and convergent thinking were used to measure creativity. A new measure of task motivation was used, together with more levels of difficulty on neuropsychological tests from the CANTAB battery., Results: Improvements under modafinil were seen on spatial working memory, planning and decision making at the most difficult levels, as well as visual pattern recognition memory following delay. Subjective ratings of enjoyment of task performance were significantly greater under modafinil compared with placebo, but mood ratings overall were not affected. The effects of modafinil on creativity were inconsistent and did not reach statistical significance., Conclusions: Modafinil reliably enhanced task enjoyment and performance on several cognitive tests of planning and working memory, but did not improve paired associates learning. The findings confirm that modafinil can enhance aspects of highly demanding cognitive performance in non-sleep deprived individuals. This article is part of a Special Issue entitled 'Cognitive Enhancers'., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Patients with major depressive disorder (MDD) usually suffer from altered cognitive functions of episodic memory, working memory, mental processing speed and motor response. Diverse studies suggest that different antidepressant agents may improve cognitive functions in patients with MDD. The aim of this work is to study the effects of serotonergic reuptake inhibitors (SSRIs) and serotonergic-noradrenergic reuptake inhibitors (SNRIs) treatments to improve the performance on memory tasks and mental processing speed in MDD. Seventy-three subjects meeting criteria for major depressive disorder were assessed with the Hamilton depression rating scale and a neuropsychological battery. The subjects were medicated with escitalopram (n=36) or duloxetine (n=37) for 24 weeks. At the end of the trial, the subjects were assessed again with the same neuropsychological battery used prior to the treatment. Both treatments improved importantly the episodic memory and to a lesser extent, working memory, mental processing speed and motor performance. Our results suggest that cognition is partially independent from improvement in clinical symptoms. Both groups achieved remission rates in the HAM-D-17 after 24 weeks of treatment, but SNRI was superior to SSRI at improving episodic and working memory. Our work indicates that the superiority of SNRI over the SSRI at episodic memory improvement is clinically relevant.

Objective: The objective of this study is to test the hypothesis that there are differences in the distribution of negative thoughts among major depressive disorders (MDD), depressive disorders among cancer patients, and IFN-alpha-induced depression., Methods: Twenty-three patients affected by MDD, 25 cancer patients affected by depressive disorders (20 MDD), and 19 patients affected by IFN-alpha-induced depression satisfying MDD criteria were evaluated using the 17-item Hamilton Depression Rating Scale and the 13-item Beck Depression Inventory., Results: Sense of guilt was higher among MDD patients (56.5%) and was lower among cancer patients (4%) (P<.0001). Sense of failure, dissatisfaction, and self-dislike were higher among MDD patients than among IFN-alpha patients (P<.0001)., Conclusions: In our study, patients affected by MDD present a different pattern of symptoms in comparison with patients affected by IFN-alpha-induced depression and depressive disorders. In particular, core depressive thoughts were less frequent in the last two conditions.

It is unclear whether changes in hostility following treatment are primarily related to improvement in depressive symptoms or are also closely associated with reductions in negative thinking or perceived stress. We evaluated 94 outpatients with major depression before and after eight weeks of fluoxetine treatment by administering the Symptom Questionnaire (SQ) Hostility Scale, the Hamilton Rating Scale for Depression (HAM-D), the Cognitions Questionnaire (CQ) and the Perceived Stress Scale (PSS). We observed significant elevations in scores on these questionnaires in depressed patients as compared to normal controls. Following treatment with fluoxetine, there was a statistically significant reduction in scores on all four questionnaires. We observed that changes in SQ Hostility were significantly positively related to changes in both depression severity and perceived stress, with these relationships remaining significant after adjusting for gender and baseline SQ Hostility. The relationship between SQ Hostility changes and reductions in negative thinking became significant only after adjusting for gender and baseline SQ hostility. Our results suggest that the marked decrease in hostility following antidepressant treatment is related to a reduction in depressive symptoms, stress levels and negative thinking.

Parkinson's disease (PD) is associated with specific cognitive deficits in the absence of dementia, including the inability to suppress previously learned responses in a changed context. Our goal was to determine whether this set-shifting deficit is sufficient to account for impaired performance on a problem-solving task, or, instead, whether it is necessary to postulate deficits in one or more other cognitive capacities, such as logical deduction. Deductive reasoning and other conceptual abilities were assessed in 15 nondemented subjects with PD who had never been medicated, 15 nondemented subjects with PD who were currently receiving medication, and 15 healthy elderly control subjects. On a deductive reasoning task, Poisoned Food Problems, the PD groups made more errors than the control group. The PD groups' error pattern was characterized by intrusions of information from previous problems. By contrast, the PD groups made appropriate assessments of redundant and irrelevant information that appeared in these problems, and performed normally on other tests of concept formation and problem solving that did not require set shifting, indicating that the capacities for logical deduction and concept formation were intact. The set-shifting deficit, conceptualized as a difficulty in suppressing a prepotent response, appears to be a primary cognitive impairment in PD and presumably arises from dysfunction of the nigrostriatal-dorsolateral prefrontal cortex complex loop.

1. Clinical and empirical evidence point to distorted negative thinking during depressive episodes. 2. The present study, utilizing the Cognitions Questionnaire, examined the thinking styles in depressed inpatients prior to antidepressant pharmacotherapy and again 3-4 weeks after treatment. 3. Across the 5 dimensions of thinking assessed, only generalization across situation changed significantly in the drug-respondent group. 4. While clinically, short-term antidepressant treatment was shown to be efficacious, it only changed cognitions in a limited way.