Biological psychiatry
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Biological psychiatry · Aug 2013
Randomized Controlled TrialA randomized trial of a low-trapping nonselective N-methyl-D-aspartate channel blocker in major depression.
The high-affinity N-methyl-D-aspartate (NMDA) antagonist ketamine exerts rapid antidepressant effects but has psychotomimetic properties. AZD6765 is a low-trapping NMDA channel blocker with low rates of associated psychotomimetic effects. This study investigated whether AZD6765 could produce rapid antidepressant effects in subjects with treatment-resistant major depressive disorder (MDD). ⋯ In patients with treatment-resistant MDD, a single intravenous dose of the low-trapping NMDA channel blocker AZD6765 was associated with rapid but short-lived antidepressant effects; no psychotomimetic effects were observed.
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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 · 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.
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Biological psychiatry · Oct 2012
Randomized Controlled Trial Clinical TrialUsing attentional bias modification as a cognitive vaccine against depression.
Negative attentional biases are thought to increase the risk of recurrence in depression, suggesting that reduction of such biases may be a plausible strategy in the secondary prevention of the illness. However, no previous study has tested whether reducing negative attentional bias causally affects risk factors for depressive recurrence. The current experimental medicine study reports the effects of a computerized attentional bias modification (ABM) procedure on intermediate measures of the risk of depressive recurrence (residual depressive symptoms and the cortisol awakening response) in patients with recurrent depression. ⋯ Positive face-based ABM was able to reduce intermediate measures of recurrence risk in previously depressed patients. These results suggest that ABM may provide a "cognitive vaccine" against depression and offer a useful strategy in the secondary prevention of the illness.
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Biological psychiatry · Jun 2012
Randomized Controlled TrialReplication of ketamine's antidepressant efficacy in bipolar depression: a randomized controlled add-on trial.
Currently, no pharmacological treatments for bipolar depression exist that exert rapid (within hours) antidepressant or antisuicidal effects. We previously reported that intravenous administration of the N-methyl-D-aspartate antagonist ketamine produced rapid antidepressant effects in patients with treatment-resistant bipolar depression. The present study sought to replicate this finding in an independent sample. ⋯ This study replicated our previous finding that patients with bipolar depression who received a single ketamine infusion experienced a rapid and robust antidepressant response. In addition, we found that ketamine rapidly improved suicidal ideation in these patients.