Biological psychiatry
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Biological psychiatry · Apr 2013
Randomized Controlled TrialRepetitive transcranial magnetic stimulation of the dorsolateral prefrontal cortex reduces nicotine cue craving.
Repetitive transcranial magnetic stimulation (rTMS) can noninvasively stimulate the brain and transiently amplify or block behaviors mediated through a region. We hypothesized that a single high-frequency rTMS session over the left dorsolateral prefrontal cortex (DLPFC) would reduce cue craving for cigarettes compared with a sham TMS session. ⋯ One session of high-frequency rTMS (10 Hz) of the left DLPFC significantly reduced subjective craving induced by smoking cues in nicotine-dependent participants. Additional studies are needed to explore rTMS as an aid to smoking cessation.
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Biological psychiatry · Jan 2013
Meta AnalysisGray matter correlates of posttraumatic stress disorder: a quantitative meta-analysis.
Since the inception of the diagnosis posttraumatic stress disorder (PTSD), attempts have been undertaken to understand why only a subpopulation of individuals exposed to trauma develops PTSD. Cerebral gray matter reductions have been suggested to be a crucial pathobiological marker of PTSD. However, a quantitative meta-analysis of whole-brain voxel-based morphometry studies is lacking. ⋯ This is the first quantitative whole-brain meta-analysis showing brain structure deficits in traumatized subjects with PTSD compared with trauma-exposed healthy control subjects. The gray matter deficit profile overlaps with brain networks of emotion processing, fear extinction, and emotion regulation known to be affected in PTSD. Although the data cannot clarify if this is a predisposition or a consequence of the disease, the results may facilitate the need to control for structural characteristics in future functional brain studies.
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Biological psychiatry · Jan 2013
Chronic pain leads to concomitant noradrenergic impairment and mood disorders.
Patients suffering chronic pain are at high risk of suffering long-lasting emotional disturbances characterized by persistent low mood and anxiety. We propose that this might be the result of a functional impairment in noradrenergic circuits associated with locus coeruleus (LC) and prefrontal cortex, where emotional and sensorial pain processes overlap. ⋯ Long-term neuropathic pain leads to anxio-depressive-like behaviors that are more predominant than the aversion of a painful experience. These changes are consistent with the impairment of noradrenergic system described in depressive disorders.
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Biological psychiatry · Nov 2012
Randomized Controlled TrialNicotine fails to attenuate ketamine-induced cognitive deficits and negative and positive symptoms in humans: implications for schizophrenia.
The uncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist, ketamine, induces a range of symptoms resembling those seen in schizophrenia. Enhancement of nicotinic acetylcholine receptor (nAChR) function may have potential as a treatment for the cognitive deficits and negative symptoms of schizophrenia. Accordingly, we examined the modulatory effects of brain nAChR systems on NMDAR antagonist-induced effects. ⋯ At blood levels comparable with tobacco smoking, nicotine infusion does not appear to alleviate the ketamine-induced transient cognitive and behavioral effects in healthy subjects that resemble those seen in schizophrenia. The lack of an effect of nicotine on a spectrum of ketamine effects suggests that the consequences of NMDAR antagonism are not likely under the direct influence of nAChR.