Oliver Mason

Risk factors for transition to first episode psychosis among individuals with 'at-risk mental states'

Recently developed criteria have been successful at identifying individuals at imminent risk of developing a psychotic disorder, but these criteria lead to 50-60% false positives. This study investigated whether measures of family history, peri-natal complications, premorbid social functioning, premorbid personality, recent life events and current symptoms would be able to improve predictions of psychosis in a group of young, help-seeking individuals who had been identified as being at risk. Individuals (N=74) were followed up at least 1 year after initial assessment. Half the sample went on to develop a psychotic disorder. The most reliable scale-based predictor was the degree of presence of schizotypal personality characteristics. However, individual items assessing odd beliefs/magical thinking, marked impairment in role functioning, blunted or inappropriate affect, anhedonia/asociality and auditory hallucinations were also highly predictive of transition, yielding good sensitivity (84%) and specificity (86%). These predictors are consistent with a picture of poor premorbid functioning that further declines in the period up to transition.

Dopaminergic foundations of schizotypy as measured by the German version of the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE)—a suitable endophenotype of schizophrenia

The concept of schizotypy or “psychosis proneness” captures individual differences in perceptual, cognitive, and affective experiences that may relate to a range of psychotic disorders. The concept is an important way to assess the contribution of pre-existing psychological and genetically based biological features to the development of illnesses such as schizophrenia (so called endophenotypes). The Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) is a widely used multi-dimensional measure of the construct and consists of four scales which mirror several groups of psychotic symptoms: Unusual Experiences (UnEx; positive symptoms), Cognitive Disorganization (CogDis; cognitive symptoms), Introvertive Anhedonia (IntAn; negative symptoms), and Impulsive Nonconformity (ImpNon; impulsive and antisocial symptoms). For the purpose of evaluating the suitability of schizotypy as an endophenotype of schizophrenia the current version of the O-LIFE was translated into German: its psychometric properties (including re-test reliability and construct validity) were examined in a large sample (n > 1200) and compared to those of the English original. The German version was both highly reliable and consistent with the original. The study aimed to show that schizotypy as measured by the O-LIFE can indeed be regarded as an endophenotype of schizophrenia in terms of genetic associations regarding relevant dopamine-related candidate polymorphisms of schizotypy [i.e., Val158Met-polymorphism of the COMT gene, uVNTR of the MAOA gene, Taq1A-polymorphism of the DRD2 gene, VNTR of the SLC6A3 (DAT) gene]. We also wanted to compare the genetic associations of the O-LIFE to those published using other operationalizations of schizotypy. Our results show a large number of significant associations and borderline-significant trends between the O-LIFE sub-scales and a range of genes, thereby supporting using the O-LIFE in the search for endophenotypic markers.

The Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE): Further description and extended norms

BACKGROUND The Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) was introduced in 1995 as a four-scale questionnaire for measuring psychosis-proneness, principally schizotypy. Its items were deliberately chosen to make it suitable for tapping psychotic characteristics in healthy individuals. Since its inception the O-LIFE has been used in a wide variety of experimental and clinical studies, establishing its reliability and validity. METHODS Data was pooled from 1926 participants together with available demographic information from several research institutions. RESULTS Extensive norms are presented by age and gender. Inter-correlations and regression equations based on age and gender are also presented. CONCLUSIONS The theoretical background and implications of work on using the O-LIFE are briefly discussed.

Short scales for measuring schizotypy

BACKGROUND This study reports short scales for measuring several dimensions of schizotypy in the normal population based on a large twin sample. METHODS The four short scales use items drawn from a longer instrument, the Oxford-Liverpool Inventory of Feelings and Experiences. Using concordance estimates from MZ and DZ pairs, the items were selected both to have a high heritability and to offer broad coverage of each trait domain. RESULTS Preliminary descriptive statistics are reported for the short scales and suggest adequate reliability. CONCLUSIONS New scales offer a time efficient and reliable method of studying proneness to psychosis in large N designs.

Neurobehavioral problems following low-level exposure to organophosphate pesticides: a systematic and meta-analytic review

Meta-analysis was carried out to determine the neurotoxic effects of long-term exposure to low levels of organophosphates (OPs) in occupational settings. Concern about the effects of OPs on human health has been growing as they are increasingly used throughout the world for a variety of agricultural, industrial and domestic purposes. The neurotoxic effects of acute poisoning are well established but the possibility that low-level exposure causes ill health is controversial. It is important to get a clear answer to this question as more individuals are at risk of low-level exposure than acute poisoning. Although a number of reviews on this topic have been published in the past, authors have come to conflicting conclusions. To date, none of these reviews have attempted quantitative evaluation of study findings using meta-analysis. This paper reviews the available evidence concerning the neurotoxicity of low-level occupational exposure to OPs and goes on to report the results of a meta-analysis of 14 studies which fulfilled criteria for this type of statistical analysis (means and standard deviations of dependant variables reported). Data were assimilated from more than 1600 participants. The majority of well designed studies found a significant association between low-level exposure to OPs and impaired neurobehavioral function which is consistent, small to moderate in magnitude and concerned primarily with cognitive functions such as psychomotor speed, executive function, visuospatial ability, working and visual memory. Unresolved issues in the literature which should become the focus of further studies are highlighted and discussed.

Cognitive therapy and behavioural coping in the management of work-related stress: An intervention study

Abstract Transactional models of stress emphasize the importance of cognitive appraisal of potential stressors in the determination of the stress response. This appraisal can be modified by the use of techniques normally associated with cognitive therapy. The contribution of a specifically cognitive component when intervening in work-related stress has not been well evaluated to date. This research seeks to determine the effectiveness of stress management training in the treatment of the work-related effects of stress by comparing the role of modifying dysfunctional cognitions with the teaching of appropriate behavioural coping strategies. Participants were allocated to one of two intervention conditions or to a waiting list control group. Those in the intervention conditions received group stress management either with the focus on delivering cognitive therapy techniques or with the focus on behavioural coping skills. Measures of general health were taken at the beginning and end of intervention and at 3-month follow-up. Participants in the cognitive therapy groups who were reporting symptoms of general ill-health at the start of the intervention showed a significant improvement at follow-up. Cognitive therapy appears to have been an effective intervention in work-related stress. Those in the behavioural group showed a smaller but still clinically effective improvement. Results are discussed in terms of methodological issues and implications for future research. It is suggested that changes in cognitive appraisal may need to be developed.

The Psychotomimetic States Inventory PSI Measuring psychotic-type experiences from ketamine and cannabis

BACKGROUND This study reports a new measure of psychotomimetic states in the context of cannabis and ketamine use. The Psychotomimetic States Inventory (PSI) has sub-scales of Delusory Thinking, Perceptual Distortions, Cognitive Disorganization, Anhedonia, Mania and Paranoia. METHODS The PSI was administered in two independent group, repeated measures designs: an experimental study of ketamine and a naturalistic study of cannabis. RESULTS Both cannabis and ketamine produced reliable increases in ratings of psychotomimetic state effects across several sub-scales. CONCLUSIONS The PSI is a potentially useful measure of the nature and extent of the phenomenological effects of psychotropic drugs in schizophrenia-related research.

Psychotic-Like Experiences, Appraisals, and Trauma

This study examined some of the predictions made by cognitive models of psychosis, specifically the potential contribution of appraisals and trauma to the development of “need for care.” Two groups reporting psychotic-like experiences with and without a “need for care” were compared on types of experiences, appraisals of these experiences, distress, and trauma. Both groups reported similar overall levels of psychotic-like experiences, but were characterized by distinct types of experiences. The clinical group was more distressed, endorsed more externalizing and personalizing appraisals, and fewer psychological/normalizing apraisals of their experiences than the nonclinical group. Both groups showed high rates of trauma, and interpersonal trauma was associated with more personalizing and fewer psychological/normalizing appraisals. These results suggest that “need for care” is characterized by distress and personalizing appraisals, but not by a higher incidence of trauma. The role of interpersonal trauma, specifically, may be to predispose to a “paranoid” world view.

Cognitive emotion regulation strategies, alexithymia and dissociation in schizophrenia, a review and meta-analysis.

AIMS Many individuals with schizophrenia are reported to have maladaptive expression and processing of emotion. This may take the form of conscious and implicit processes. Potential regulatory processes underlying schizophrenia are reviewed. We aimed to estimate effect sizes, potential heterogeneity and publication bias across three areas of measurement: a range of cognitive emotion regulation strategies(1) (CERS), alexithymia and dissociation. METHOD Data were pooled from 47 case-control studies involving measures of experiential avoidance, attentional deployment, cognitive reappraisal, emotion management, dissociation and alexithymia. All studies were rated for quality, risk of bias and publication bias. RESULTS The following effect sizes (g) were observed: emotion management: 0.96 [0.77, 1.14] and cognitive reappraisal: 0.49 [0.32, 0.66] were negatively associated with schizophrenia. Experiential avoidance: -0.44 [-0.59, -0.29], attentional deployment -0.96 [-1.18, -0.75], dissociation: -0.86 [-1.13, -0.60] and alexithymia: -1.05 [-1.45, -0.65] were positively associated with schizophrenia. Subgroups of dissociation and attentional deployment were also analysed. Meta-analyses revealed potential publication bias and heterogeneity in the study of CERS in schizophrenia. CONCLUSIONS A marked difference in the implementation of CERS is associated with schizophrenia compared to controls. Dissociation variables and alexithymia are also indicated and may be implicated in adaptive cognitive emotional regulation. Theoretical and research implications are discussed.

Mental health and physical activity interventions: A review of the qualitative literature

Background Interventions based on physical activity are of proven efficacy as adjunctive interventions in mental health, but less is known about how these benefits come about. Aims This review summarises the qualitative research on the perspectives of service users so as to shed light on possible psychological and social mechanisms of therapeutic change. Method Thirteen published studies were identified by a detailed search of the peer-reviewed literature employing a variety of methodologies across a range of physical activity contexts for participants with severe and enduring mental health difficulties. The results are grouped thematically, and the studies were compared and contrasted with respect to methodology and findings. Findings There was a high degree of congruence in support of the themes of social interaction and social support; feeling safe; improved symptoms; a sense of meaning, purpose and achievement; identity and the role of the facilitating personnel. Conclusions Exercise interventions deserve greater emphasis both theoretically and clinically, as many service users experience them as socially inclusive, non-stigmatising and, above all, effective in aiding recovery.