Psychiatry research
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Psychiatry research · Mar 2011
Defensive startle response to emotional social cues in social anxiety.
Potentiation of fear-related defense behaviours coordinated by the amygdala in response to environmental threat characterizes several anxiety disorders. We compared eye-blink startle responses to startle probes delivered during the presentation of emotional and neutral social cues in high and low generalized social anxiety. Socially anxious individuals exhibited larger startle responses to emotional (positive and negative) relative to neutral social cues, compared to non-anxious individuals.
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Psychiatry research · Feb 2011
Subjective awareness of everyday dysexecutive behavior precedes 'objective' executive problems in schizotypy: a replication and extension study.
This study aimed to examine the subjective awareness of everyday dysexecutive function and the 'objective' executive function in individuals with schizotypal personality features. Forty-nine individuals with schizotypal personality disorder (SPD) proneness (25 negative schizotypy and 24 non-negative schizotypy were identified using cluster analysis) and 44 non-SPD individuals completed a battery of 'objective' executive function tests and a self-reported Dysexecutive Questionnaire (DEX) on everyday executive problems. ⋯ Furthermore, SPD proneness, especially negative schizotypy was found to give undependable estimation on their everyday dysexecutive function while non-negative schizotypy was not. The current findings suggest that the subjective awareness of dysexecutive function may precede actual 'objective' executive function impairments in a subtype of SPD (non-negative schizotypy) and the subjective complaint of the daily dysexecutive behavior in SPD proneness, especially negative schizotypy might result from their unreliable estimation of executive function.
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Psychiatry research · Jan 2011
Perceptual bias of patients with schizophrenia in morphed facial expression.
Limited research has specifically examined the nature of the dysfunction in emotion categorization representation in schizophrenia. The current study aimed to investigate the perception bias of morphed facial expression in subjects with schizophrenia and healthy controls in the emotion continua. Twenty-eight patients with schizophrenia and thirty-one healthy controls took part in this study. ⋯ They were sensitive to sadness (a smaller shift point) and the perception changed rapidly (a sharper response slope) as compared with healthy controls in the emotion continuum of happy to sad. In conclusion, patients with schizophrenia demonstrated impaired categorical perception of facial expressions, with generally 'rapid' but 'late' discrimination towards social threat-related stimuli such as angry facial expression. Compared with healthy controls, these patients have a sharper discrimination perception pattern in the emotion continua from positive valence to negative valence.
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Psychiatry research · Dec 2010
Emotional interference in obsessive-compulsive disorder: a neuropsychological study using optimized emotional Stroop test.
Contents related to threat and associated cognitive processes are proposed to be the central characteristic of obsessive-compulsive disorder (OCD) according to 'threat-relatedness hypothesis'. However, evidence for attention bias toward emotionally salient stimuli using the emotional Stroop test is equivocal. This discrepancy could be due to methodological issues, mainly differences in the lexical characters of words. ⋯ There were no significant correlations between other illness-related variables (age at onset, illness duration, and medication dose) and Stroop test performance. Study findings suggest the presence of selective emotional bias for OCD relevant stimuli in these patients and this bias is potentially related to symptomatic status. These observations are in tune with the threat-relatedness hypothesis.
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Psychiatry research · Dec 2010
Randomized Controlled TrialThe acute and late CNS glutamine response to benzodiazepine challenge: a pilot pharmacokinetic study using proton magnetic resonance spectroscopy.
Benzodiazepines (BZs), which are typically used as anxiolytics, act by modulating inhibitory signaling through gamma-aminobutyric acid A (GABA)(A) receptors. Functionally, the inhibitory effects of GABA may be counterbalanced by the excitatory effects of glutamate (Glu) as the two neurotransmitter systems are metabolically linked through their synthetic intermediate glutamine (Gln). The primary aim of this study was to determine whether the effects of different BZs on the GABA and Glu/Gln systems would vary according to the pharmacokinetics of the different drugs. ⋯ In post-hoc comparisons, the difference in the Gln to creatine (Cr) ratio was 0.04 for the BZs versus placebo at 1h and 0.01 at 10h following the administration of drug (t(11)=2.49, P=0.03 1 h; t(10)=0.65, P=0.53 10 h; no correction for multiple comparisons). An increase in Gln/Cr at 1 h post-BZ is consistent with a functionally synergistic relationship between Glu/Gln and GABA in the brain. It also suggests that MRS may have sufficient sensitivity to detect acute drug effects.