Filippo Varese | Lancaster University (original) (raw)

Papers by Filippo Varese

The British journal of clinical psychology / the British Psychological Society, 2014

The study examined (1) the role of experiential avoidance (EA), conceptualized as intolerance tow... more The study examined (1) the role of experiential avoidance (EA), conceptualized as intolerance towards aversive mental states, in paranoid delusions and (2) the mechanisms underlying EA. A 6-day prospective momentary assessment study. Paranoid patients (N = 41) were studied using the experience sampling method (ESM), a structured diary technique, assessing psychopathology and current context in daily life. The results showed that both low self-esteem and EA contributed to paranoid thinking. The relationship between low self-esteem and paranoia was partially mediated by EA and the relationship between EA and paranoia was partially mediated by low self-esteem. The detrimental effect of EA on self-esteem was more pronounced under high activity-related stress. Both EA and social stress were independently associated with low self-esteem. EA was associated with self-esteem instability. Our results implicate mental control strategies in the development of paranoia and are compatible with th...

Schizophrenia bulletin, 2012

Evidence suggests that adverse experiences in childhood are associated with psychosis. To examine... more Evidence suggests that adverse experiences in childhood are associated with psychosis. To examine the association between childhood adversity and trauma (sexual abuse, physical abuse, emotional/psychological abuse, neglect, parental death, and bullying) and psychosis outcome, MEDLINE, EMBASE, PsychINFO, and Web of Science were searched from January 1980 through November 2011. We included prospective cohort studies, large-scale cross-sectional studies investigating the association between childhood adversity and psychotic symptoms or illness, case-control studies comparing the prevalence of adverse events between psychotic patients and controls using dichotomous or continuous measures, and case-control studies comparing the prevalence of psychotic symptoms between exposed and nonexposed subjects using dichotomous or continuous measures of adversity and psychosis. The analysis included 18 case-control studies (n = 2048 psychotic patients and 1856 nonpsychiatric controls), 10 prospecti...

Although there is considerable evidence that adversities in childhood such as social deprivation,... more Although there is considerable evidence that adversities in childhood such as social deprivation, sexual abuse, separation from parents, neglect and exposure to deviant parental communication are associated with psychosis in later life, most studies have considered broad diagnoses as outcomes. In this review we consider evidence for pathways between specific types of adversity and specific symptoms of psychosis. We present theoretical arguments for expecting some degree of specificity (although by no means perfect specificity) between different kinds of adversity and different symptoms of psychosis. We review studies that have investigated social-environmental risk factors for thought disorder, auditory-verbal hallucinations and paranoid delusions, and consider how these risk factors may impact on specific psychological and biological mechanisms. Communication deviance in parents has been implicated in the development of thought disorder in offspring, childhood sexual abuse has been particularly implicated in auditory-verbal hallucinations, and attachment-disrupting events (e.g. neglect, being brought up in an institution) may have particular potency for the development of paranoid symptoms. Current research on psychological mechanisms underlying these symptoms suggests a number of symptom-specific mechanisms that may explain these associations. Few studies have considered symptoms, underlying mechanisms and different kinds of adversity at the same time. Future research along these lines will have the potential to elucidate the mechanisms that lead to severe mental illness, and may have considerable clinical implications.

The Neuroscience of Hallucinations, 2012

Philosophy and Psychology, 2013

Schizophrenia Bulletin, 2013

Background: Parental communication deviance (CD) has long been suggested as a potential risk fact... more Background: Parental communication deviance (CD) has long been suggested as a potential risk factor for the development of psychosis and thought disorder in genetically sensitive offspring. However, the findings of the studies on the prevalence of CD in parents of psychotic patients have never been submitted to quantitative synthesis. Method: PsycINFO was searched from January 1959 to January 2012 for studies on the prevalence of CD in parents of psychotic patients. This search was supplemented with the results from a much larger systematic search (PsycINFO, PubMed, EMBASE, and Web of Science) on childhood trauma and psychosis. Results: A total of 20 retrieved studies (n = 1753 parents) yielded a pooled g of large magnitude (0.97; 95% CI [0.76; 1.18]) with a significant amount of heterogeneity (Q = 33.63; P = .014; I 2 = 46.47). Subgroup and sensitivity analysis of methodological features (study's design, comparison group, diagnostic criteria, CD rating method, inter-rater reliability not reported, year of publication, and verbosity) and demographic characteristics (level of education or offspring's age) revealed that pooled effect size was stable and unlikely to have been affected by these features. Conclusion: CD is highly prevalent in parents of psychotic offspring. This is discussed in the broader context of adoption and longitudinal studies that have reported a G × E interaction in the development of psychosis and thought disorder. A potential developmental mechanism is suggested to explain how CD may affect the developing offspring. The importance of further studies on CD and its potential value as a clinical concept are discussed.

Schizophrenia Bulletin, 2012

Previous studies have reported associations between childhood adversities, eg, loss of a parent, ... more Previous studies have reported associations between childhood adversities, eg, loss of a parent, being raised in institutional care, sexual and other kinds of abuse by adults and bullying by peers, and psychosis in adulthood. However, the mechanisms by which these adversities lead to psychotic experiences are poorly understood. From models of the psychological processes involved in positive symptoms, it was predicted that childhood sexual abuse would be specifically associated with auditory hallucinations in adulthood, and that disruption of early attachment relations and more chronic forms of victimization such as bullying would be specifically associated with paranoid ideation. We therefore examined the associations between sexual trauma, physical abuse, bullying, and being brought up in institutional or local authority care and reports of auditory hallucinations and paranoid beliefs in the 2007 Adult Psychiatric Morbidity Survey. All simple associations between childhood adversities and the two symptom types were significant. Childhood rape was associated only with hallucinations (OR 8.9, CI = 1.86-42.44) once co-occurring paranoia was controlled for. Being brought up in institutional care (OR = 11.08, CI = 3.26-37.62) was specifically associated with paranoia once comorbid hallucinations had been controlled for. For each symptom, dose-response relationships were observed between the number of childhood traumas and the risk of the symptom. The specific associations observed are consistent with current psychological theories about the origins of hallucinations and paranoia. Further research is required to study the psychological and biological mediators of these associations.

Schizophrenia Bulletin, 2012

Evidence suggests that adverse experiences in childhood are associated with psychosis. To examine... more Evidence suggests that adverse experiences in childhood are associated with psychosis. To examine the association between childhood adversity and trauma (sexual abuse, physical abuse, emotional/psychological abuse, neglect, parental death, and bullying) and psychosis outcome, MEDLINE, EMBASE, PsychINFO, and Web of Science were searched from January 1980 through November 2011. We included prospective cohort studies, large-scale crosssectional studies investigating the association between childhood adversity and psychotic symptoms or illness, case-control studies comparing the prevalence of adverse events between psychotic patients and controls using dichotomous or continuous measures, and case-control studies comparing the prevalence of psychotic symptoms between exposed and nonexposed subjects using dichotomous or continuous measures of adversity and psychosis. The analysis included 18 case-control studies (n 5 2048 psychotic patients and 1856 nonpsychiatric controls), 10 prospective and quasi-prospective studies (n 5 41 803) and 8 population-based cross-sectional studies (n 5 35 546). There were significant associations between adversity and psychosis across all research designs, with an overall effect of OR 5 2.78 (95% CI 5 2.34-3.31). The integration of the case-control studies indicated that patients with psychosis were 2.72 times more likely to have been exposed to childhood adversity than controls (95% CI 5 1.90-3.88). The association between childhood adversity and psychosis was also significant in populationbased cross-sectional studies (OR 5 2.99 [95% CI 5 2.12-4.20]) as well as in prospective and quasiprospective studies (OR 5 2.75 [95% CI 5 2.17-3.47]). The estimated population attributable risk was 33% (16%-47%). These findings indicate that childhood adversity is strongly associated with increased risk for psychosis.

Schizophrenia Bulletin, 2012

While the majority of cognitive studies on auditory hallucinations (AHs) have been conducted in s... more While the majority of cognitive studies on auditory hallucinations (AHs) have been conducted in schizophrenia (SZ), an increasing number of researchers are turning their attention to different clinical and nonclinical populations, often using SZ findings as a model for research. Recent advances derived from SZ studies can therefore be utilized to make substantial progress on AH research in other groups. The objectives of this article were to (1) present an up-to-date review regarding the cognitive mechanisms of AHs in SZ, (2) review findings from cognitive research conducted in other clinical and nonclinical groups, and (3) integrate these recent findings into a cohesive framework. First, SZ studies show that the cognitive underpinnings of AHs include self-source-monitoring deficits and executive and inhibitory control dysfunctions as well as distortions in top-down mechanisms, perceptual and linguistic processes, and emotional factors. Second, consistent with SZ studies, findings in other population groups point to the role of top-down processing, abnormalities in executive inhibition, and negative emotions. Finally, we put forward an integrated model of AHs that incorporates the above findings. We suggest that AHs arise from an interaction between abnormal neural activation patterns that produce salient auditory signals and top-down mechanisms that include signal detection errors, executive and inhibition deficits, a tapestry of expectations and memories, and state characteristics that influence how these experiences are interpreted. Emotional factors play a particular prominent role at all levels of this hierarchy. Our model is distinctively powerful in explaining a range of phenomenological characteristics of AH across a spectrum of disorders.

Psychosis, 2014

ABSTRACT Objective: Experience sampling (ES) involves participants rating ambulant phenomena at u... more ABSTRACT Objective: Experience sampling (ES) involves participants rating ambulant phenomena at unpredictable intervals. Despite its perceived benefits, there is little published research evaluating the limitations of this method. Method: Predictors of compliance were investigated across three studies using ES in psychotic populations. Results: Regression analyses indicated that none of the demographic or clinical variables significantly (p .05) predicted the number of valid reports or compliance as defined by traditionally used cut-off points ( 33%). Conclusions: We conclude that it is difficult to predict compliance in ES research, which is likely to be an accessible methodology, even for people experiencing distressing symptoms.

Psychosis, 2011

... [CrossRef], [PubMed], [Web of Science ®] View all references; Hammersley et al., 200326. Hamm... more ... [CrossRef], [PubMed], [Web of Science ®] View all references; Hammersley et al., 200326. Hammersley, P., Dias, A., Todd, G., Bowen‐Jones, K., Reilly, B. and Bentall, RP 2003. Childhood trauma and hallucinations in bipolar affective disorder: Preliminary investigation. ...

Psychosis, 2012

ABSTRACT In light of critiques of the first meta-analysis of studies examining the relationship o... more ABSTRACT In light of critiques of the first meta-analysis of studies examining the relationship of childhood adversities to psychosis, two of the authors of the meta-analysis ask whether the same criteria are used to evaluate bio-genetic and psycho-social research into the causes of psychosis.

Psychological Medicine, 2013

Although depression and mania are often assumed to be polar opposites, studies have shown that, i... more Although depression and mania are often assumed to be polar opposites, studies have shown that, in patients with bipolar disorder, they are weakly positively correlated and vary somewhat independently over time. Thus, when investigating relationships between specific psychological processes and specific symptoms (mania and depression), co-morbidity between the symptoms and changes over time must be taken into account. Method A total of 253 bipolar disorder patients were assessed every 24 weeks for 18 months using the Hamilton Rating Scale for Depression (HAMD), the Bech-Rafaelsen Mania Assessment Scale (MAS), the Rosenberg Self-Esteem Questionnaire (RSEQ), the Dysfunctional Attitudes Scale (DAS), the Internal, Personal and Situational Attributions Questionnaire (IPSAQ) and the Personal Qualities Questionnaire (PQQ). We calculated multilevel models using the xtreg module of Stata 9.1, with psychological and clinical measures nested within each participant. Mania and depression were weakly, yet significantly, associated; each was related to distinct psychological processes. Cross-sectionally, self-esteem showed the most robust associations with depression and mania: depression was associated with low positive and high negative self-esteem, and mania with high positive self-esteem. Depression was significantly associated with most of the other self-referential measures, whereas mania was weakly associated only with the externalizing bias of the IPSAQ and the achievement scale of the DAS. Prospectively, low self-esteem predicted future depression. The associations between different self-referential thinking processes and different phases of bipolar disorder, and the presence of the negative self-concept in both depression and mania, have implications for therapeutic management, and also for future directions of research.

Psychological Medicine, 2013

Cognitive models have postulated that auditory hallucinations arise from the misattribution of in... more Cognitive models have postulated that auditory hallucinations arise from the misattribution of internally generated cognitive events to external sources. Several experimental paradigms have been developed to assess this externalizing bias in clinical and non-clinical hallucination-prone samples, including source-monitoring, verbal self-monitoring and auditory signal detection tasks. This meta-analysis aims to synthesize the wealth of empirical findings from these experimental studies. A database search was carried out for reports between January 1985 and March 2012. Additional studies were retrieved by contacting authors and screening references of eligible reports. Studies were considered eligible if they compared either (i) hallucinating and non-hallucinating patients with comparable diagnoses, or (ii) non-clinical hallucination-prone and non-prone participants using source-monitoring, verbal self-monitoring or signal detection tasks, or used correlational analyses to estimate comparable effects. The analysis included 15 clinical (240 hallucinating patients and 249 non-hallucinating patients) and nine non-clinical studies (171 hallucination-prone and 177 non-prone participants; 57 participants in a correlation study). Moderate-to-large summary effects were observed in both the clinical and analogue samples. Robust and significant effects were observed in source-monitoring and signal detection studies, but not in self-monitoring studies, possibly due to the small numbers of eligible studies in this subgroup. The use of emotionally valenced stimuli led to effects of similar magnitude to the use of neutral stimuli. The findings suggest that externalizing biases are important cognitive underpinnings of hallucinatory experiences. Clinical interventions targeting these biases should be explored as possible treatments for clients with distressing voices.

Psychological Medicine, 2012

Background. It has been proposed that the relationship between childhood trauma and hallucination... more Background. It has been proposed that the relationship between childhood trauma and hallucinations can be explained by dissociative processes. The present study examined whether the effect of childhood trauma on hallucination-proneness is mediated by dissociative tendencies. In addition, the influence of dissociative symptoms on a cognitive process believed to underlie hallucinatory experiences (i.e. reality discrimination ; the capacity to discriminate between internal and external cognitive events) was also investigated.

PLoS ONE, 2013

Background: Previous research has suggested that the way bipolar patients respond to depressive m... more Background: Previous research has suggested that the way bipolar patients respond to depressive mood impacts on the future course of the illness, with rumination prolonging depression and risk-taking possibly triggering hypomania. However, the relationship over time between variables such as mood, self-esteem, and response style to negative affect is complex and has not been directly examined in any previous study -an important limitation, which the present study seeks to address.

Neuropsychology, 2014

Objective: Chemotherapy-induced cognitive impairments are reported by many cancer survivors. Rese... more Objective: Chemotherapy-induced cognitive impairments are reported by many cancer survivors. Research to date has not provided a clear description of their nature, extent, mechanisms, and duration. To investigate the impairments and factors that could influence their identification and severity, the present meta-analysis brings together research on this topic in adult cancer patients. Method: Our random-model meta-analysis includes 44 studies investigating the cognitive performance of adults treated with chemotherapy for non-central nervous system malignancies, primarily breast and testicular cancer. We conducted several subgroup analyses to identify the level of cognitive impairments in longitudinal and cross-sectional studies. We also pursued several multilevel model regressions to investigate the impact of methodological (study quality) and clinical moderators (diagnosis, age, time since treatment) on the observed effect sizes. Results: Cognitive impairments were found in cross-sectional studies in immediate free recall, delayed memory, verbal memory, delayed recognition memory, selective attention, and attention capacity. Surprisingly, prior to chemotherapy, patients performed better than matched controls. In longitudinal studies, patients' performance increased from baseline to follow-up, an effect that was stronger in patients than controls. None of the chosen moderators influenced the magnitude of estimated summary effect sizes. Conclusions: The likelihood to identify impairments rests on the type of design employed, as memory and attention impairments are only detected in cross-sectional studies. We discuss the lack of significant impact of moderators on the effect sizes despite the heterogeneity of results, while providing recommendations toward decreasing the heterogeneity in future studies.

The British journal of clinical psychology / the British Psychological Society, 2014

The study examined (1) the role of experiential avoidance (EA), conceptualized as intolerance tow... more The study examined (1) the role of experiential avoidance (EA), conceptualized as intolerance towards aversive mental states, in paranoid delusions and (2) the mechanisms underlying EA. A 6-day prospective momentary assessment study. Paranoid patients (N = 41) were studied using the experience sampling method (ESM), a structured diary technique, assessing psychopathology and current context in daily life. The results showed that both low self-esteem and EA contributed to paranoid thinking. The relationship between low self-esteem and paranoia was partially mediated by EA and the relationship between EA and paranoia was partially mediated by low self-esteem. The detrimental effect of EA on self-esteem was more pronounced under high activity-related stress. Both EA and social stress were independently associated with low self-esteem. EA was associated with self-esteem instability. Our results implicate mental control strategies in the development of paranoia and are compatible with th...

Schizophrenia bulletin, 2012

Evidence suggests that adverse experiences in childhood are associated with psychosis. To examine... more Evidence suggests that adverse experiences in childhood are associated with psychosis. To examine the association between childhood adversity and trauma (sexual abuse, physical abuse, emotional/psychological abuse, neglect, parental death, and bullying) and psychosis outcome, MEDLINE, EMBASE, PsychINFO, and Web of Science were searched from January 1980 through November 2011. We included prospective cohort studies, large-scale cross-sectional studies investigating the association between childhood adversity and psychotic symptoms or illness, case-control studies comparing the prevalence of adverse events between psychotic patients and controls using dichotomous or continuous measures, and case-control studies comparing the prevalence of psychotic symptoms between exposed and nonexposed subjects using dichotomous or continuous measures of adversity and psychosis. The analysis included 18 case-control studies (n = 2048 psychotic patients and 1856 nonpsychiatric controls), 10 prospecti...

Although there is considerable evidence that adversities in childhood such as social deprivation,... more Although there is considerable evidence that adversities in childhood such as social deprivation, sexual abuse, separation from parents, neglect and exposure to deviant parental communication are associated with psychosis in later life, most studies have considered broad diagnoses as outcomes. In this review we consider evidence for pathways between specific types of adversity and specific symptoms of psychosis. We present theoretical arguments for expecting some degree of specificity (although by no means perfect specificity) between different kinds of adversity and different symptoms of psychosis. We review studies that have investigated social-environmental risk factors for thought disorder, auditory-verbal hallucinations and paranoid delusions, and consider how these risk factors may impact on specific psychological and biological mechanisms. Communication deviance in parents has been implicated in the development of thought disorder in offspring, childhood sexual abuse has been particularly implicated in auditory-verbal hallucinations, and attachment-disrupting events (e.g. neglect, being brought up in an institution) may have particular potency for the development of paranoid symptoms. Current research on psychological mechanisms underlying these symptoms suggests a number of symptom-specific mechanisms that may explain these associations. Few studies have considered symptoms, underlying mechanisms and different kinds of adversity at the same time. Future research along these lines will have the potential to elucidate the mechanisms that lead to severe mental illness, and may have considerable clinical implications.

The Neuroscience of Hallucinations, 2012

Philosophy and Psychology, 2013

Schizophrenia Bulletin, 2013

Background: Parental communication deviance (CD) has long been suggested as a potential risk fact... more Background: Parental communication deviance (CD) has long been suggested as a potential risk factor for the development of psychosis and thought disorder in genetically sensitive offspring. However, the findings of the studies on the prevalence of CD in parents of psychotic patients have never been submitted to quantitative synthesis. Method: PsycINFO was searched from January 1959 to January 2012 for studies on the prevalence of CD in parents of psychotic patients. This search was supplemented with the results from a much larger systematic search (PsycINFO, PubMed, EMBASE, and Web of Science) on childhood trauma and psychosis. Results: A total of 20 retrieved studies (n = 1753 parents) yielded a pooled g of large magnitude (0.97; 95% CI [0.76; 1.18]) with a significant amount of heterogeneity (Q = 33.63; P = .014; I 2 = 46.47). Subgroup and sensitivity analysis of methodological features (study's design, comparison group, diagnostic criteria, CD rating method, inter-rater reliability not reported, year of publication, and verbosity) and demographic characteristics (level of education or offspring's age) revealed that pooled effect size was stable and unlikely to have been affected by these features. Conclusion: CD is highly prevalent in parents of psychotic offspring. This is discussed in the broader context of adoption and longitudinal studies that have reported a G × E interaction in the development of psychosis and thought disorder. A potential developmental mechanism is suggested to explain how CD may affect the developing offspring. The importance of further studies on CD and its potential value as a clinical concept are discussed.

Schizophrenia Bulletin, 2012

Previous studies have reported associations between childhood adversities, eg, loss of a parent, ... more Previous studies have reported associations between childhood adversities, eg, loss of a parent, being raised in institutional care, sexual and other kinds of abuse by adults and bullying by peers, and psychosis in adulthood. However, the mechanisms by which these adversities lead to psychotic experiences are poorly understood. From models of the psychological processes involved in positive symptoms, it was predicted that childhood sexual abuse would be specifically associated with auditory hallucinations in adulthood, and that disruption of early attachment relations and more chronic forms of victimization such as bullying would be specifically associated with paranoid ideation. We therefore examined the associations between sexual trauma, physical abuse, bullying, and being brought up in institutional or local authority care and reports of auditory hallucinations and paranoid beliefs in the 2007 Adult Psychiatric Morbidity Survey. All simple associations between childhood adversities and the two symptom types were significant. Childhood rape was associated only with hallucinations (OR 8.9, CI = 1.86-42.44) once co-occurring paranoia was controlled for. Being brought up in institutional care (OR = 11.08, CI = 3.26-37.62) was specifically associated with paranoia once comorbid hallucinations had been controlled for. For each symptom, dose-response relationships were observed between the number of childhood traumas and the risk of the symptom. The specific associations observed are consistent with current psychological theories about the origins of hallucinations and paranoia. Further research is required to study the psychological and biological mediators of these associations.

Schizophrenia Bulletin, 2012

Evidence suggests that adverse experiences in childhood are associated with psychosis. To examine... more Evidence suggests that adverse experiences in childhood are associated with psychosis. To examine the association between childhood adversity and trauma (sexual abuse, physical abuse, emotional/psychological abuse, neglect, parental death, and bullying) and psychosis outcome, MEDLINE, EMBASE, PsychINFO, and Web of Science were searched from January 1980 through November 2011. We included prospective cohort studies, large-scale crosssectional studies investigating the association between childhood adversity and psychotic symptoms or illness, case-control studies comparing the prevalence of adverse events between psychotic patients and controls using dichotomous or continuous measures, and case-control studies comparing the prevalence of psychotic symptoms between exposed and nonexposed subjects using dichotomous or continuous measures of adversity and psychosis. The analysis included 18 case-control studies (n 5 2048 psychotic patients and 1856 nonpsychiatric controls), 10 prospective and quasi-prospective studies (n 5 41 803) and 8 population-based cross-sectional studies (n 5 35 546). There were significant associations between adversity and psychosis across all research designs, with an overall effect of OR 5 2.78 (95% CI 5 2.34-3.31). The integration of the case-control studies indicated that patients with psychosis were 2.72 times more likely to have been exposed to childhood adversity than controls (95% CI 5 1.90-3.88). The association between childhood adversity and psychosis was also significant in populationbased cross-sectional studies (OR 5 2.99 [95% CI 5 2.12-4.20]) as well as in prospective and quasiprospective studies (OR 5 2.75 [95% CI 5 2.17-3.47]). The estimated population attributable risk was 33% (16%-47%). These findings indicate that childhood adversity is strongly associated with increased risk for psychosis.

Schizophrenia Bulletin, 2012

While the majority of cognitive studies on auditory hallucinations (AHs) have been conducted in s... more While the majority of cognitive studies on auditory hallucinations (AHs) have been conducted in schizophrenia (SZ), an increasing number of researchers are turning their attention to different clinical and nonclinical populations, often using SZ findings as a model for research. Recent advances derived from SZ studies can therefore be utilized to make substantial progress on AH research in other groups. The objectives of this article were to (1) present an up-to-date review regarding the cognitive mechanisms of AHs in SZ, (2) review findings from cognitive research conducted in other clinical and nonclinical groups, and (3) integrate these recent findings into a cohesive framework. First, SZ studies show that the cognitive underpinnings of AHs include self-source-monitoring deficits and executive and inhibitory control dysfunctions as well as distortions in top-down mechanisms, perceptual and linguistic processes, and emotional factors. Second, consistent with SZ studies, findings in other population groups point to the role of top-down processing, abnormalities in executive inhibition, and negative emotions. Finally, we put forward an integrated model of AHs that incorporates the above findings. We suggest that AHs arise from an interaction between abnormal neural activation patterns that produce salient auditory signals and top-down mechanisms that include signal detection errors, executive and inhibition deficits, a tapestry of expectations and memories, and state characteristics that influence how these experiences are interpreted. Emotional factors play a particular prominent role at all levels of this hierarchy. Our model is distinctively powerful in explaining a range of phenomenological characteristics of AH across a spectrum of disorders.

Psychosis, 2014

ABSTRACT Objective: Experience sampling (ES) involves participants rating ambulant phenomena at u... more ABSTRACT Objective: Experience sampling (ES) involves participants rating ambulant phenomena at unpredictable intervals. Despite its perceived benefits, there is little published research evaluating the limitations of this method. Method: Predictors of compliance were investigated across three studies using ES in psychotic populations. Results: Regression analyses indicated that none of the demographic or clinical variables significantly (p .05) predicted the number of valid reports or compliance as defined by traditionally used cut-off points ( 33%). Conclusions: We conclude that it is difficult to predict compliance in ES research, which is likely to be an accessible methodology, even for people experiencing distressing symptoms.

Psychosis, 2011

... [CrossRef], [PubMed], [Web of Science ®] View all references; Hammersley et al., 200326. Hamm... more ... [CrossRef], [PubMed], [Web of Science ®] View all references; Hammersley et al., 200326. Hammersley, P., Dias, A., Todd, G., Bowen‐Jones, K., Reilly, B. and Bentall, RP 2003. Childhood trauma and hallucinations in bipolar affective disorder: Preliminary investigation. ...

Psychosis, 2012

ABSTRACT In light of critiques of the first meta-analysis of studies examining the relationship o... more ABSTRACT In light of critiques of the first meta-analysis of studies examining the relationship of childhood adversities to psychosis, two of the authors of the meta-analysis ask whether the same criteria are used to evaluate bio-genetic and psycho-social research into the causes of psychosis.

Psychological Medicine, 2013

Although depression and mania are often assumed to be polar opposites, studies have shown that, i... more Although depression and mania are often assumed to be polar opposites, studies have shown that, in patients with bipolar disorder, they are weakly positively correlated and vary somewhat independently over time. Thus, when investigating relationships between specific psychological processes and specific symptoms (mania and depression), co-morbidity between the symptoms and changes over time must be taken into account. Method A total of 253 bipolar disorder patients were assessed every 24 weeks for 18 months using the Hamilton Rating Scale for Depression (HAMD), the Bech-Rafaelsen Mania Assessment Scale (MAS), the Rosenberg Self-Esteem Questionnaire (RSEQ), the Dysfunctional Attitudes Scale (DAS), the Internal, Personal and Situational Attributions Questionnaire (IPSAQ) and the Personal Qualities Questionnaire (PQQ). We calculated multilevel models using the xtreg module of Stata 9.1, with psychological and clinical measures nested within each participant. Mania and depression were weakly, yet significantly, associated; each was related to distinct psychological processes. Cross-sectionally, self-esteem showed the most robust associations with depression and mania: depression was associated with low positive and high negative self-esteem, and mania with high positive self-esteem. Depression was significantly associated with most of the other self-referential measures, whereas mania was weakly associated only with the externalizing bias of the IPSAQ and the achievement scale of the DAS. Prospectively, low self-esteem predicted future depression. The associations between different self-referential thinking processes and different phases of bipolar disorder, and the presence of the negative self-concept in both depression and mania, have implications for therapeutic management, and also for future directions of research.

Psychological Medicine, 2013

Cognitive models have postulated that auditory hallucinations arise from the misattribution of in... more Cognitive models have postulated that auditory hallucinations arise from the misattribution of internally generated cognitive events to external sources. Several experimental paradigms have been developed to assess this externalizing bias in clinical and non-clinical hallucination-prone samples, including source-monitoring, verbal self-monitoring and auditory signal detection tasks. This meta-analysis aims to synthesize the wealth of empirical findings from these experimental studies. A database search was carried out for reports between January 1985 and March 2012. Additional studies were retrieved by contacting authors and screening references of eligible reports. Studies were considered eligible if they compared either (i) hallucinating and non-hallucinating patients with comparable diagnoses, or (ii) non-clinical hallucination-prone and non-prone participants using source-monitoring, verbal self-monitoring or signal detection tasks, or used correlational analyses to estimate comparable effects. The analysis included 15 clinical (240 hallucinating patients and 249 non-hallucinating patients) and nine non-clinical studies (171 hallucination-prone and 177 non-prone participants; 57 participants in a correlation study). Moderate-to-large summary effects were observed in both the clinical and analogue samples. Robust and significant effects were observed in source-monitoring and signal detection studies, but not in self-monitoring studies, possibly due to the small numbers of eligible studies in this subgroup. The use of emotionally valenced stimuli led to effects of similar magnitude to the use of neutral stimuli. The findings suggest that externalizing biases are important cognitive underpinnings of hallucinatory experiences. Clinical interventions targeting these biases should be explored as possible treatments for clients with distressing voices.

Psychological Medicine, 2012

Background. It has been proposed that the relationship between childhood trauma and hallucination... more Background. It has been proposed that the relationship between childhood trauma and hallucinations can be explained by dissociative processes. The present study examined whether the effect of childhood trauma on hallucination-proneness is mediated by dissociative tendencies. In addition, the influence of dissociative symptoms on a cognitive process believed to underlie hallucinatory experiences (i.e. reality discrimination ; the capacity to discriminate between internal and external cognitive events) was also investigated.

PLoS ONE, 2013

Background: Previous research has suggested that the way bipolar patients respond to depressive m... more Background: Previous research has suggested that the way bipolar patients respond to depressive mood impacts on the future course of the illness, with rumination prolonging depression and risk-taking possibly triggering hypomania. However, the relationship over time between variables such as mood, self-esteem, and response style to negative affect is complex and has not been directly examined in any previous study -an important limitation, which the present study seeks to address.

Neuropsychology, 2014

Objective: Chemotherapy-induced cognitive impairments are reported by many cancer survivors. Rese... more Objective: Chemotherapy-induced cognitive impairments are reported by many cancer survivors. Research to date has not provided a clear description of their nature, extent, mechanisms, and duration. To investigate the impairments and factors that could influence their identification and severity, the present meta-analysis brings together research on this topic in adult cancer patients. Method: Our random-model meta-analysis includes 44 studies investigating the cognitive performance of adults treated with chemotherapy for non-central nervous system malignancies, primarily breast and testicular cancer. We conducted several subgroup analyses to identify the level of cognitive impairments in longitudinal and cross-sectional studies. We also pursued several multilevel model regressions to investigate the impact of methodological (study quality) and clinical moderators (diagnosis, age, time since treatment) on the observed effect sizes. Results: Cognitive impairments were found in cross-sectional studies in immediate free recall, delayed memory, verbal memory, delayed recognition memory, selective attention, and attention capacity. Surprisingly, prior to chemotherapy, patients performed better than matched controls. In longitudinal studies, patients' performance increased from baseline to follow-up, an effect that was stronger in patients than controls. None of the chosen moderators influenced the magnitude of estimated summary effect sizes. Conclusions: The likelihood to identify impairments rests on the type of design employed, as memory and attention impairments are only detected in cross-sectional studies. We discuss the lack of significant impact of moderators on the effect sizes despite the heterogeneity of results, while providing recommendations toward decreasing the heterogeneity in future studies.