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Preethi Premkumar

Bio: Preethi Premkumar is an academic researcher from Nottingham Trent University. The author has contributed to research in topics: Schizophrenia & Schizotypy. The author has an hindex of 22, co-authored 47 publications receiving 1487 citations. Previous affiliations of Preethi Premkumar include London South Bank University & Royal College of Psychiatrists.


Papers
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Journal ArticleDOI
TL;DR: For people with early psychosis, early intervention services appear to have clinically important benefits over standard care and including CBT and family intervention within the service may contribute to improved outcomes in this critical period.
Abstract: Background Early intervention services for psychosis aim to detect emergent symptoms, reduce the duration of untreated psychosis, and improve access to effective treatments. Aims To evaluate the effectiveness of early intervention services, cognitive–behavioural therapy (CBT) and family intervention in early psychosis. Method Systematic review and meta-analysis of randomised controlled trials of early intervention services, CBT and family intervention for people with early psychosis. Results Early intervention services reduced hospital admission, relapse rates and symptom severity, and improved access to and engagement with treatment. Used alone, family intervention reduced relapse and hospital admission rates, whereas CBT reduced the severity of symptoms with little impact on relapse or hospital admission. Conclusions For people with early psychosis, early intervention services appear to have clinically important benefits over standard care. Including CBT and family intervention within the service may contribute to improved outcomes in this critical period. The longer-term benefits of this approach and its component treatments for people with early and established psychosis need further research.

396 citations

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TL;DR: DLPFC activity and its connectivity with the cerebellum predict responsiveness to CBT for psychosis in schizophrenia and these effects may be mediated by PFC–cerebellum contributions to executive processing.

108 citations

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TL;DR: A meta-analysis of existing double-blind randomized placebo-controlled studies looking at the addition of the second-generation antipsychotic quetiapine in patients with obsessive–compulsive disorder showed evidence of efficacy for adjunctive quetuapine on the primary efficacy criterion, but the clinical significance was limited by between-study heterogeneity.
Abstract: Small studies have shown positive effects from adding a variety of antipsychotic agents in patients with obsessive-compulsive disorder who are unresponsive to treatment with serotonin reuptake inhibitors. The evidence, however, is contradictory. This paper reports a meta-analysis of existing double-blind randomized placebo-controlled studies looking at the addition of the second-generation antipsychotic quetiapine in such cases. Three studies fulfilled the inclusion criteria. Altogether 102 individuals were subjected to analysis using Review Manager (4.2.7). The results showed evidence of efficacy for adjunctive quetiapine (<400 mg/day) on the primary efficacy criterion, measured as changes from baseline in total Yale-Brown Obsessive Compulsive Scale scores (P=0.008), the clinical significance of which was limited by between-study heterogeneity. The mechanism underlying the effect may involve serotonin and/or dopamine neurotransmission.

90 citations

Journal ArticleDOI
TL;DR: The findings show a bias towards misattributing fearful and angry facial emotions and the propensity for fear-as-anger misattribution biases increases as the length of time that the disorder is experienced increases and a more rigid style of information processing is used.

78 citations

Journal ArticleDOI
01 Oct 2008-Cortex
TL;DR: The findings of this study are consistent with previous suggestions of susceptibility of PPI to cognitive processes controlled in a ‘top down’ manner by the cortex and the hypothesis that compromised neural resources in the frontal cortex contribute to reduced PPI in schizophrenia.

68 citations


Cited by
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Journal ArticleDOI
TL;DR: The evidence-base of CBT is very strong and the strongest support exists for CBT of anxiety disorders, somatoform disorders, bulimia, anger control problems, and general stress.
Abstract: Cognitive behavioral therapy (CBT) refers to a popular therapeutic approach that has been applied to a variety of problems. The goal of this review was to provide a comprehensive survey of meta-analyses examining the efficacy of CBT. We identified 269 meta-analytic studies and reviewed of those a representative sample of 106 meta-analyses examining CBT for the following problems: substance use disorder, schizophrenia and other psychotic disorders, depression and dysthymia, bipolar disorder, anxiety disorders, somatoform disorders, eating disorders, insomnia, personality disorders, anger and aggression, criminal behaviors, general stress, distress due to general medical conditions, chronic pain and fatigue, distress related to pregnancy complications and female hormonal conditions. Additional meta-analytic reviews examined the efficacy of CBT for various problems in children and elderly adults. The strongest support exists for CBT of anxiety disorders, somatoform disorders, bulimia, anger control problems, and general stress. Eleven studies compared response rates between CBT and other treatments or control conditions. CBT showed higher response rates than the comparison conditions in seven of these reviews and only one review reported that CBT had lower response rates than comparison treatments. In general, the evidence-base of CBT is very strong. However, additional research is needed to examine the efficacy of CBT for randomized-controlled studies. Moreover, except for children and elderly populations, no meta-analytic studies of CBT have been reported on specific subgroups, such as ethnic minorities and low income samples.

2,107 citations

Journal ArticleDOI
TL;DR: Functional magnetic resonance imaging studies have revealed that the DMN in the healthy brain is associated with stimulus-independent thought and self-reflection and that greater suppression of theDMN isassociated with better performance on attention-demanding tasks.
Abstract: Neuropsychiatric disorders are associated with abnormal function of the default mode network (DMN), a distributed network of brain regions more active during rest than during performance of many attention-demanding tasks and characterized by a high degree of functional connectivity (i.e., temporal correlations between brain regions). Functional magnetic resonance imaging studies have revealed that the DMN in the healthy brain is associated with stimulus-independent thought and self-reflection and that greater suppression of the DMN is associated with better performance on attention-demanding tasks. In schizophrenia and depression, the DMN is often found to be hyperactivated and hyperconnected. In schizophrenia this may relate to overly intensive self-reference and impairments in attention and working memory. In depression, DMN hyperactivity may be related to negative rumination. These findings are considered in terms of what is known about psychological functions supported by the DMN, and alteration of the DMN in other neuropsychiatric disorders.

1,137 citations

Journal ArticleDOI
01 Apr 2008-Brain
TL;DR: It is demonstrated that the brain functional networks had efficient small-world properties in the healthy subjects; whereas these properties were disrupted in the patients with schizophrenia, consistent with a hypothesis of dysfunctional integration of the brain in this illness.
Abstract: The human brain has been described as a large, sparse, complex network characterized by efficient small-world properties, which assure that the brain generates and integrates information with high efficiency. Many previous neuroimaging studies have provided consistent evidence of ‘dysfunctional connectivity’ among the brain regions in schizophrenia; however, little is known about whether or not this dysfunctional connectivity causes disruption of the topological properties of brain functional networks. To this end, we investigated the topological properties of human brain functional networks derived from resting-state functional magnetic resonance imaging (fMRI). Data was obtained from 31 schizophrenia patients and 31 healthy subjects; then functional connectivity between 90 cortical and sub-cortical regions was estimated by partial correlation analysis and thresholded to construct a set of undirected graphs. Our findings demonstrated that the brain functional networks had efficient small-world properties in the healthy subjects; whereas these properties were disrupted in the patients with schizophrenia. Brain functional networks have efficient small-world properties which support efficient parallel information transfer at a relatively low cost. More importantly, in patients with schizophrenia the small-world topological properties are significantly altered in many brain regions in the prefrontal, parietal and temporal lobes. These findings are consistent with a hypothesis of dysfunctional integration of the brain in this illness. Specifically, we found that these altered topological measurements correlate with illness duration in schizophrenia. Detection and estimation of these alterations could prove helpful for understanding the pathophysiological mechanism as well as for evaluation of the severity of schizophrenia.

1,021 citations

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TL;DR: This Review explores whether these alterations reflect toxic effects of early-life stress or potentially adaptive modifications, the relationship between psychopathology and brain changes, and the distinction between resilience, susceptibility and compensation.
Abstract: Maltreatment-related childhood adversity is the leading preventable risk factor for mental illness and substance abuse. Although the association between maltreatment and psychopathology is compelling, there is a pressing need to understand how maltreatment increases the risk of psychiatric disorders. Emerging evidence suggests that maltreatment alters trajectories of brain development to affect sensory systems, network architecture and circuits involved in threat detection, emotional regulation and reward anticipation. This Review explores whether these alterations reflect toxic effects of early-life stress or potentially adaptive modifications, the relationship between psychopathology and brain changes, and the distinction between resilience, susceptibility and compensation.

982 citations