Psychiatry research
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Psychiatry research · Mar 2007
Randomized Controlled Trial Multicenter Study Comparative StudyCharacteristics of smokers with a psychotic disorder and implications for smoking interventions.
Despite high rates of smoking among people with psychotic disorders, and the associated health and financial burden, few studies have investigated the characteristics of this group of smokers. This paper reports data from 298 smokers with an ICD-10 psychotic disorder residing in the community (56.7% with schizophrenia or schizoaffective disorder), including an examination of their demographic and clinical characteristics, smoking behaviours, severity of nicotine dependence, stage of change, and reasons for smoking and for quitting. Standardized self-report instruments were used, in conjunction with structured interviews, as part of the first phase of a randomized controlled trial. ⋯ The present sample was also more likely to report stress reduction, stimulation and addiction as reasons for smoking, compared to a general sample of smokers. Males, precontemplators and participants with concurrent hazardous substance use cited fewer reasons for quitting smoking. These and other subgroup differences in smoking characteristics are used to illustrate potential implications for the nature and timing of smoking interventions among people with a psychotic disorder.
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Psychiatry research · Jan 2007
Amygdala reactivity predicts automatic negative evaluations for facial emotions.
The amygdala is a key structure in a limbic circuit involved in the rapid and unconscious processing of facial emotions. In the present study, the role of the amygdala in automatic, involuntary appraisal processes, which are believed to be a crucial component of emotion processing, was investigated in 23 healthy subjects. Amygdala activity was recorded in response to masked displays of angry, sad, and happy facial expressions using functional magnetic resonance imaging (fMRI). ⋯ Significant correlations were found between amygdala responses to masked negative facial expressions and negative evaluation shifts elicited by the corresponding emotion quality in the affective priming task. Spontaneous amygdala reactivity to facial emotions appears to be a determinant of automatic negative evaluative response tendencies. This finding might shed some light on how amygdala hyperresponsivity contributes to negative cognitive biases commonly observed in affective disorders.
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Psychiatry research · Jan 2007
Dissociation of cognitive from affective components of theory of mind in schizophrenia.
Patients suffering from schizophrenia show impaired emotional and social behavior, such as misinterpretation of social situations and lack of theory of mind. However, there is conflicting evidence regarding their ability to perform on theory of mind tasks. Based on previous findings with patients suffering from prefrontal damage, the present study suggests that the behavioral deficit of schizophrenic patients may be due to impaired 'affective theory of mind' abilities, rather than to a general impairment in theory of mind. ⋯ Furthermore, correlation analysis indicated that impaired affective theory of mind in these patients correlated with their level of negative symptoms. These results indicate that individuals with high level of negative symptoms of schizophrenia may demonstrate selective impairment in their ability to attribute affective mental states. These findings offer new insight into the affective facets of social behavior that may underlie the profound behavioral disturbances observed in schizophrenia.
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Psychiatry research · Dec 2006
Single voxel proton magnetic resonance spectroscopy in post-stroke depression.
Mood disorders are associated with structural, metabolic and spectroscopic changes in prefrontal regions. In the case of depression associated with stroke, there is little information about the biochemical profile of these regions, as assessed by proton magnetic resonance spectroscopy ((1)H-MRS). In a group of first-ever stroke patients, we studied the association between post-stroke depression and (1)H-MRS measurements in unaffected frontal lobes. ⋯ Patients with depression in the immediate post-stroke phase had significantly higher Glx/Cr ratios in the contralesional hemisphere than non-depressive patients. No biochemical differences were found between the groups at 4-month follow-up. These findings suggest that post-stroke depression is accompanied by changes in frontal lobe glutamate/glutamine levels, perhaps reflecting abnormalities in glutamatergic transmission in the immediate post-stroke period.
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Psychiatry research · Nov 2006
The neural correlates of habituation of response to startling tactile stimuli presented in a functional magnetic resonance imaging environment.
Functional magnetic resonance imaging (fMRI) provides a means of identifying neural circuitry associated with startle and its modulation in humans. Twelve subjects who demonstrated eyeblink startle in the laboratory were recruited for an fMRI study in which they were scanned while presented with two identical runs consisting of alternating blocks of no stimuli and startling tactile stimuli. Together, behavioral and imaging data are consistent with a pattern of general cortical and thalamic activation induced by startling stimuli that shows habituation both across and within runs. ⋯ A similar graded decrease was observed in the thalamus signal, as well. Thus, startling tactile stimuli initially induce widespread cortical and thalamic activity, perhaps mediated by the reticular activating system. The activity then habituates in a graded fashion with repeated presentations of the stimuli.