Neural correlates of executive function and working memory in the 'at risk mental state'

Background and Aims: People with ‘prodromal’ symptoms have a very high risk of developing psychosis. We used functional MRI to examine the neurocognitive basis of this vulnerability. Method: Cross-sectional comparison of subjects with an ARMS (n=17), first episode schizophreniform psychosis (n=10) and healthy volunteers (n=15). Subjects were studied using functional MRI while they performed an overt verbal fluency task, a random movement generation paradigm and an N-Back working memory task. Results: During an N-Back task the ARMS group engaged inferior frontal and posterior parietal cortex less than controls but more than the first episode group. During a motor generation task, the ARMS group showed less activation in the left inferior parietal cortex than controls, but greater activation than the first episode group. During verbal fluency using ‘Easy’ letters, the ARMS group demonstrated intermediate activation in the left inferior frontal cortex, with first episode groups showing least, and controls most, activation. When processing ‘Hard’ letters, differential activation was evident in two left inferior frontal regions. In its dorsolateral portion, the ARMS group showed less activation than controls but more than the first episode group, while in the opercular part of the left inferior frontal gyrus / anterior insula activation was greatest in the first episode group, weakest in controls and intermediate in the ARMS group. Conclusions: The ARMS is associated with abnormalities of regional brain function that are qualitatively similar to those in patients who have just developed psychosis but less severe

White matter alterations related to P300 abnormalities in individuals at high risk for psychosis: an MRI–EEG study

Background: Psychosis onset is characterized by white matter and electrophysiologic abnormalities. The relation between these factors in the development of illness is almost unknown. We studied the relation between white matter volumes and P300 in prodromal psychosis. Methods: We assessed white matter volume (detected using magnetic resonance imaging) and electrophysiologic response during an oddball task (P300) in healthy controls and individuals at high clinical risk for psychosis (with an " at-risk mental state " [ARMS]). Results: We included 41 controls and 39 patients with an ARMS in our study. A psychotic disorder developed in 26% of the ARMS group within the follow-up period of 2 years. The P300 amplitude was significantly lower in the ARMS group than in the control group. The ARMS group showed reduced volume of white matter underlying the left superior temporal gyrus and the left superior frontal gyrus and increased volume of white matter underlying the right insula and the right angular gyrus compared with controls. Relative to individ -uals who did not later become psychotic, the subgroup in whom psychosis subsequently developed had a smaller volume of white matter underlying the left precuneus and the right middle temporal gyrus and increased volume in the white matter underlying the right middle frontal gyrus. We observed a significant interaction in the right middle frontal gyrus: white matter volume was negatively associated with P300 amplitude in the ARMS group and positively associated with P300 amplitude in the control group. Limitations: The voxel-based morphometry method alone cannot determine whether abnormal white matter volumes are due to an altered number of axonal connections or decreased myelination. Conclusion: P300 abnormalities precede the onset of psychosis and are directly related to white matter alterations, representing a correlate of an increased vulnerability to disease.© 2011 Canadian Medical Association

Major research project: the influence of experience and reasoning on delusion formation

This study tested two theoretical models of delusion formation. The first suggests that most delusions are caused by the application of normal reasoning to abnormal experiences (Maher, 1974; 1988; 1992). The second suggests that many delusions are caused by an information-processing bias that results in both abnormal reasoning and abnormal experiences (Garety & Hemsley, 1994). The first model predicts that people with delusions, who demonstrate a "jump-to-conclusions" bias, will experience less perceptual anomalies (e.g. hallucinations) than those who do not. The second model predicts that people with delusions, who demonstrate a "jump-to-conclusions" bias, will experience more perceptual anomalies than those who do not. The second model also predicts that the "jump-to-conclusions" bias will be associated with a failure to make use of past regularities when processing new stimuli and a deficiency in the meta-cognitive skill of reality discrimination. The presence of a "jump-to-conclusions" bias in fifty adults with delusions was assessed by their performance on a probabilistic inference task. The performance of the 22 participants who demonstrated the bias, was compared with the performance of the 28 participants, in whom the bias was absent, on three computer-based tasks and two structured interviews, which sought to measure perceptual anomalies, reality discrimination and the use of past regularities in processing new stimuli. Results indicated that people with delusions, who demonstrate a "jump-to-conclusions" bias, experienced less hallucinations than those who do not, thus supporting Maher's model. Experiences of voices commenting, olfactory hallucinations, visual hallucinations and general auditory hallucinations were more common in participants without a "jump- to-conclusions" bias. The "jump-to-conclusions" bias was not associated with a failure to make use of past regularities when processing new stimuli nor with a deficiency in the meta-cognitive skill of reality discrimination, thus contradicting Garety & Hemsley's model. A deficiency in auditory reality discrimination was associated with the experience of voices commenting. A deficiency in visual reality discrimination was associated with a failure to make use of past regularities when processing new stimuli although this information-processing bias was not observed in the sample as a whole. It was concluded that there is considerable variation between individuals in the factors that result in delusions. Despite contradicting some specific predictions of Garety & Hemsley's (1994) model, the findings are consistent with a multi-factorial model of delusion formation. The relationship between these factors would be demonstrated more clearly by the identification of these factors in case studies of individuals with delusions, than by the identification of differences between groups of people with and without delusions. The mechanisms that connect these factors to psychotic phenomena would be elucidated by case studies that specify patients' experiences and cognitive biases in more detail than studies of heterogeneous groups

Improving attitudes toward electroconvulsive therapy

Aims and method Electroconvulsive therapy (ECT) often causes fear in the general public because of media representation and negative reported side-effects. This study evaluates a new video focusing on experiences of ECT and how this can aid communicating medical information to the public. Knowledge and attitudes toward ECT after watching the video were compared with a group that received no information and a group that read the current NHS leaflet on ECT. The role of empathy was also considered as a covariate. Results The video was the only condition found to positively affect knowledge and attitudes toward ECT. The video was especially beneficial to those that possessed low perspective-taking trait empathy. Clinical implications These findings demonstrate the video improved knowledge and attitudes toward ECT compared with current material or no information. We suggest that the addition of personal experiences to public information adds perspective, improving overall attitudes toward health treatments. </jats:sec

Cognitive behavioral therapy across the stages of psychosis:Prodromal, first episode, and chronic schizophrenia

Since the early 1990s, cognitive behavioral therapy (CBT) has been increasingly used as an adjunctive treatment for psychotic disorders. This paper describes the CBT of three cases, each at a different stage of psycholic disorder: at-risk mental state, first-episode psychosis, and chronic psychotic disorder For the at-risk mental state, treament focused on anxiety and social phobia, whereas the treatment of first-episode psychosis focused on the development of a shared formulation of the factors leading to and maintaining psychotic symptoms. For the chronic case, treatment emphasized the possibility of improving strategies to Prevent symptoms from interfering with life goals. The potential contribution of CBT to improve outcomes in psychotic disorders beyond those obtained through traditional pharmacotheropy is discussed

Jumping to perceptions and to conclusions:Specificity to hallucinations and delusions

BackgroundThere is evidence that people with psychosis display a “jump-to-conclusions” (JTC) reasoning style, and that this bias may be specific to delusions. A “jump-to-perceptions” (JTP) cognitive bias has also been found and is typically linked to hallucinations. However, there is some evidence for an association between JTP and delusions, and its specificity to hallucinations remains unclear. It has been suggested that these biases are related and products of shared cognitive processes.MethodsThis study examined the symptom specificity of JTC and JTP, and the relationship between them, in a sample of 98 individuals with delusions divided into ‘hallucinators’ (n = 51) and ‘non-hallucinators’ (n = 47). Biases were assessed using the beads task and visual and auditory perceptual tasks.ResultsAs predicted, both groups demonstrated a JTC bias, but the ‘hallucinators’ showed a more pronounced JTP style in both modalities. The presence of JTC and JTP biases did not co-occur: making a decision on the beads task after two or fewer draws was not related to visual JTP, and was associated with a less marked JTP bias in the auditory perceptual task. No differences were found in JTP or JTC between participants with and without a schizophrenia diagnosis. JTP, but not JTC, was associated with the presence of hallucinations.ConclusionsThese findings suggest that the JTC and JTP biases show specificity to delusions and hallucinations, respectively, and not to diagnosis. There was no evidence that they are the product of shared cognitive processes, further supporting their specificity