Papers by Irina Falkenberg
Social cognitive and affective neuroscience, Jan 25, 2015
Neurobiological and behavioral findings suggest that psychosis is associated with corticolimbic h... more Neurobiological and behavioral findings suggest that psychosis is associated with corticolimbic hyperactivity during the processing of emotional salience. This has not been widely studied in the early stages of psychosis the impact of these abnormalities on psychotic symptoms and global functioning is unknown. We sought to address this issue in 18 patients with first-episode psychosis (FEP), 18 individuals at ultra-high risk of psychosis (UHR), and 22 healthy controls. Corticolimbic response and subjective ratings to emotional and neutral scenes were measured using functional MRI. The clinical and functional impact of corticolimbic abnormalities was assessed with regression analyses. The FEP and UHR groups reported increased subjective emotional arousal to neutral scenes compared with healthy controls. Across groups, emotional versus neutral scenes elicited activation in the dorsomedial prefrontal cortex, inferior frontal gyrus/anterior insula, and amygdala. Although FEP and UHR par...
Current Psychiatry Reports, 2011
The diagnosis of bipolar affective disorder (BD) is often delayed, and preceded by incorrect diag... more The diagnosis of bipolar affective disorder (BD) is often delayed, and preceded by incorrect diagnoses and potentially harmful treatment, while the development of the disorder is associated with suicidal behavior and help seeking. Several clinical features have been linked to an increased risk of going on to develop BD, in particular attenuated symptoms of BD, personality traits such as cyclothymia, and general psychopathologic symptoms. Several of these show high specificity, indicating that it may be possible to target detection and intervention in individuals at high risk of BD and perhaps moderate the course of the illness and improve treatment outcome. This article summarizes recent evidence on the characteristics of the prodrome to BD and discusses the potential value and challenges of early detection and intervention in BD.
Neuropsychopharmacology, 2014
There is now considerable evidence to support the hypothesis that psychotic symptoms are the resu... more There is now considerable evidence to support the hypothesis that psychotic symptoms are the result of abnormal salience attribution, and that the attribution of salience is largely mediated through the prefrontal cortex, the striatum, and the hippocampus. Although these areas show differential activation under the influence of delta-9-tetrahydrocannabinol (delta-9-THC) and cannabidiol (CBD), the two major derivatives of cannabis sativa, little is known about the effects of these cannabinoids on the functional connectivity between these regions. We investigated this in healthy occasional cannabis users by employing event-related functional magnetic resonance imaging (fMRI) following oral administration of delta-9-THC, CBD, or a placebo capsule. Employing a seed cluster-based functional connectivity analysis that involved using the average time series from each seed cluster for a whole-brain correlational analysis, we investigated the effect of drug condition on functional connectivity between the seed clusters and the rest of the brain during an oddball salience processing task. Relative to the placebo condition, delta-9-THC and CBD had opposite effects on the functional connectivity between the dorsal striatum, the prefrontal cortex, and the hippocampus. Delta-9-THC reduced fronto-striatal connectivity, which was related to its effect on task performance, whereas this connection was enhanced by CBD. Conversely, mediotemporal-prefrontal connectivity was enhanced by delta-9-THC and reduced by CBD. Our results suggest that the functional integration of brain regions involved in salience processing is differentially modulated by single doses of delta-9-THC and CBD and that this relates to the processing of salient stimuli.Neuropsychopharmacology advance online publication, 18 February 2015;doi:10.1038/npp.2014.258.
Schizophrenia Research, 2014
Schizophrenia Research, Apr 30, 2012
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Papers by Irina Falkenberg