Psychiatry research
-
Psychiatry research · Aug 2010
Functional magnetic resonance imaging response to experimental pain in drug-free patients with schizophrenia.
Clinical evidence suggests that there is decreased pain sensitivity in schizophrenia; however, the neurobiological mechanism of this decrease remains unknown. Using functional magnetic resonance imaging, we examined the blood oxygen level-dependent (BOLD) changes induced by experimental pain-tolerance (endure) hot stimuli vs. non-painful stimuli during an acute psychotic episode in 12 drug-free patients with schizophrenia and in 13 gender- and age-matched healthy controls. The analyses revealed that patients showed a greater BOLD response at S1 compared with controls but a reduced BOLD response in the posterior cingulate cortex (PCC), insula, and brainstem during pain-tolerance stimuli. ⋯ S1 BOLD response positively correlated with unpleasantness in patients but not in controls. These initial results confirm that unmedicated patients with schizophrenia have a higher pain tolerance than controls, decreased activation in pain affective-cognitive processing regions (insula, PCC, brainstem), and an over-activation of the primary sensory-discriminative pain processing region (S1). These pilot results are the first to explore the mechanism driving altered pain sensitivity in schizophrenia.
-
Psychiatry research · Jul 2010
Region and diagnosis-specific changes in synaptic proteins in schizophrenia and bipolar I disorder.
Aberrant regulation of synaptic function is thought to play a role in the aetiology of psychiatric disorders, including schizophrenia and bipolar disorder. Normal neurotransmitter release is dependent on a complex group of presynaptic proteins that regulate synaptic vesicle docking, membrane fusion and fission, including synaptophysin, syntaxin, synaptosomal-associated protein-25 (SNAP-25), vesicle-associated membrane protein (VAMP), alpha-synuclein and dynamin I. In addition, structural and signalling proteins such as neural cell adhesion molecule (NCAM) maintain the integrity of the synapse. ⋯ In schizophrenia, a significant reduction in the ratio of the two major membrane-bound forms of NCAM (180 and 140) was observed in BA10. The distinct functions of these two NCAM forms suggest that changes in the comparative levels of these proteins could lead to a destabilisation of synaptic signalling. Our data support the notion that there are complex and region-specific alterations in presynaptic proteins that may lead to alterations in synaptic activity in both schizophrenia and bipolar disorder.
-
Psychiatry research · Jul 2010
Demographic and social variables associated with problem gambling among men and women in Canada.
Knowledge of demographic and social correlates of problem gambling among men and women in general population samples is limited. Such research is important for identifying individuals who may become problem gamblers. The current research used a gender-stratified analysis using logistic regression models in a nationally representative sample to identify correlates of problem gambling among men and women. ⋯ For women, increased odds of problem gambling was associated with middle age, middle to low levels of income, a high school diploma or less, being never-married, higher levels of life stress, and negative coping abilities. For men, being aged 70 or greater decreased the odds of problem gambling, while being separated, widowed, or divorced, lower levels of social support, and negative coping abilities increased the odds of problem gambling. These findings have important public health implications for identifying men and women who may be more likely to become problem gamblers in the general population.
-
Psychiatry research · Jun 2010
Validating a new clinical subtyping scheme for delirium with electronic motion analysis.
The usefulness of motor subtypes of delirium is unclear due to inconsistency in sub-typing methods and a lack of validation with objective measures of activity. The activity of 40 patients was measured with 24 h accelerometry monitoring. Patients with Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) delirium (n=30) were allocated into hyperactive, hypoactive and mixed motor subtypes. ⋯ Differences were greater in the daytime and during the early evening 'sundowning' period. Frequency of postural changes was the most discriminating measure examined. Clinical subtypes of delirium defined by observed motor behaviour on the ward differ in electronically measured activity levels.
-
Psychiatry research · May 2010
Voxel-based morphometry in eating disorders: correlation of psychopathology with grey matter volume.
Twenty-nine adult female patients with eating disorders (17 with bulimia nervosa, 12 with restrictive anorexia nervosa) were compared with 18 age-matched female healthy controls, using voxel-based morphometry. Restrictive anorexia nervosa patients showed a decrease of grey matter, particularly affecting the anterior cingulate cortex, frontal operculum, temporoparietal regions and the precuneus. By contrast, patients with bulimia nervosa did not differ from healthy controls. ⋯ The strong reduction of grey matter volume in adult patients with restrictive anorexia nervosa is in line with results of adolescent patients. Contrary to other studies, this first voxel-based morphometry report of bulimic patients did not find any structural abnormalities. The inferior parietal cortex is a critical region for sensory integration of body and spatial perception, and the correlation of "drive for thinness" with grey matter volume of this region points to a neural correlate of this core psychopathological feature of eating disorders.