Gillian A. Doody

Theory of mind and psychoses

BACKGROUND A cardinal feature of schizophrenia is the sufferers difficulty in interacting appropriately within the social milieu. This deficit has recently been associated with the concept of theory of mind, more commonly constructed as a working model to understand behavioural patterns in autistic children. In this paper the complex relationships between theory of mind, IQ and psychoses are addressed. METHODS Five experimental groups were used; non-psychiatric controls, affective disorder, schizophrenia with normal pre-morbid IQ, schizophrenia with pre-morbid IQ in the mildly learning disabled range, and mild learning disability with no history of psychiatric illness. All subjects were given a first order Theory of Mind Task and if successful, a second order Theory of Mind Task was then administered. All subjects were rated using the Positive and Negative Symptom Scale (PANSS). RESULTS Subjects with schizophrenia and subjects with mild learning disability show impaired ability on a second order theory of mind task. However, when patients who are unable to answer reality questions are removed from the analysis specific impairment of theory of mind is only seen in subjects with schizophrenia. Furthermore, this impairment is relatively specific to particular psychopathological clusters in subjects with schizophrenia. Even though the same clusters of psychopathology are also seen in patients with affective disorder, their presence is not associated with poor second order theory of mind performance. CONCLUSIONS Impaired theory of mind on second order tests is specific to schizophrenia when compared to mild learning disability and affective disorder control groups. Subjects with schizophrenia and pre-morbid mild learning disability show greater impairment than subjects with schizophrenia and a pre-morbid IQ within the normal range.

Parental separation, loss and psychosis in different ethnic groups: a case-control study

BACKGROUND Numerous studies have reported high rates of psychosis in the Black Caribbean and Black African populations in the UK. However, few studies have investigated the role of specific risk factors in different ethnic groups. We sought to investigate the relationship between long-term separation from, and death of, a parent before the age of 16 and risk of adult psychosis in different ethnic groups. METHOD All patients with a first episode of psychosis who made contact with psychiatric services in defined catchment areas in London and Nottingham, UK and a series of community controls were included in the AESOP (Aetiology and Ethnicity in Schizophrenia and Other Psychoses) study. Data relating to clinical and social variables, including parental separation and loss, were collected from patients and controls. RESULTS Separation from, and death of, a parent before the age of 16 were both strongly associated with a two- to threefold increased risk of psychosis. The strength of these associations were similar for White British and Black Caribbean (but not Black African) subjects. Separation from (but not death of) a parent was more common among Black Caribbean controls than White British controls. CONCLUSIONS Early separation may have a greater impact in the Black Caribbean population, because it is more common, and may contribute to the excess of psychosis in this population.

Specific and Generalized Neuropsychological Deficits: A Comparison of Patients With Various First-Episode Psychosis Presentations

OBJECTIVE Overwhelming evidence suggests that compromised neuropsychological function is frequently observed in schizophrenia. Neurocognitive dysfunction has often been reported in other psychotic disorders, although there are inconsistencies in the literature. In the context of four distinct diagnostic groups, the authors compared neuropsychological performance among patients experiencing their first psychotic episode. METHOD Data were derived from a population-based, case-control study of patients with first-episode psychosis. A neuropsychological test battery was administered to patients with a diagnosis of schizophrenia (N=65), bipolar disorder or mania (N=37), depressive psychosis (N=39), or other psychotic disorders (N=46) following index presentation, as well as to healthy comparison subjects (N=177). The presence of specific and generalized cognitive deficits was examined. RESULTS The schizophrenia group presented widespread neuropsychological impairments and performed significantly worse than healthy comparison subjects on most neuropsychological measures. Patients with other psychotic disorders and depressive psychosis also demonstrated widespread impairments. Deficits in patients with bipolar disorder or mania were less pervasive but evident in performance scores on verbal memory and fluency tests. Differences between the four patient groups and healthy comparison subjects and among the patient groups were attenuated after controlling for differences in general cognitive ability (IQ). CONCLUSIONS Early in their course, cognitive deficits are present in all psychotic disorders but are most severe and pervasive in schizophrenia and least pervasive in bipolar disorder and mania.

The varying impact of type, timing and frequency of exposure to childhood adversity on its association with adult psychotic disorder

BACKGROUND Childhood adversity has been associated with onset of psychosis in adulthood but these studies have used only general definitions of this environmental risk indicator. Therefore, we sought to explore the prevalence of more specific adverse childhood experiences amongst those with and without psychotic disorders using detailed assessments in a large epidemiological case-control sample (AESOP). METHOD Data were collected on 182 first-presentation psychosis cases and 246 geographically matched controls in two UK centres. Information relating to the timing and frequency of exposure to different types of childhood adversity (neglect, antipathy, physical and sexual abuse, local authority care, disrupted living arrangements and lack of supportive figure) was obtained using the Childhood Experience of Care and Abuse Questionnaire. RESULTS Psychosis cases were three times more likely to report severe physical abuse from the mother that commenced prior to 12 years of age, even after adjustment for other significant forms of adversity and demographic confounders. A non-significant trend was also evident for greater prevalence of reported severe maternal antipathy amongst those with psychosis. Associations with maternal neglect and childhood sexual abuse disappeared after adjusting for maternal physical abuse and antipathy. Paternal maltreatment and other forms of adversity were not associated with psychosis nor was there evidence of a dose-response effect. CONCLUSIONS These findings suggest that only specific adverse childhood experiences are associated with psychotic disorders and only in a minority of cases. If replicated, this greater precision will ensure that research into the mechanisms underlying the pathway from childhood adversity to psychosis is more fruitful.

Gender differences in the association between childhood abuse and psychosis

BACKGROUND Studies demonstrating an association between childhood trauma and psychosis in adulthood have not systematically explored gender differences. AIMS To investigate gender differences in the prevalence of childhood sexual and physical abuse among people with psychosis in comparison with healthy controls. METHOD The Childhood Experiences of Care and Abuse Questionnaire was completed to elicit experiences of sexual and physical abuse during childhood in first-episode psychosis cases and population-based controls. RESULTS Among women, those in the cases group were twice as likely to report either physical or sexual abuse compared with controls following adjustment for all confounders. In particular, the effect of physical abuse in women was stronger and more robust than that for sexual abuse. A similar trend was found for psychotic-like experiences in the female control group. No association was found in men. CONCLUSIONS Reports of severe childhood physical or sexual abuse were associated with psychosis in women but not in men.

Cumulative social disadvantage, ethnicity and first-episode psychosis: a case-control study

BACKGROUND Numerous studies have reported high rates of psychosis in the Black Caribbean population in the UK. Recent speculation about the reasons for these high rates has focused on social factors. However, there have been few empirical studies. We sought to compare the prevalence of specific indicators of social disadvantage and isolation, and variations by ethnicity, in subjects with a first episode of psychosis and a series of healthy controls. METHOD All cases with a first episode of psychosis who made contact with psychiatric services in defined catchment areas in London and Nottingham, UK and a series of community controls were recruited over a 3-year period. Data relating to clinical and social variables were collected from cases and controls. RESULTS On all indicators, cases were more socially disadvantaged and isolated than controls, after controlling for potential confounders. These associations held when the sample was restricted to those with an affective diagnosis and to those with a short prodrome and short duration of untreated psychosis. There was a clear linear relationship between concentrated disadvantage and odds of psychosis. Similar patterns were evident in the two main ethnic groups, White British and Black Caribbean. However, indicators of social disadvantage and isolation were more common in Black Caribbean subjects than White British subjects. CONCLUSIONS We found strong associations between indicators of disadvantage and psychosis. If these variables index exposure to factors that increase risk of psychosis, their greater prevalence in the Black Caribbean population may contribute to the reported high rates of psychosis in this population.

Individualized prediction of illness course at the first psychotic episode: a support vector machine MRI study

Background To date, magnetic resonance imaging (MRI) has made little impact on the diagnosis and monitoring of psychoses in individual patients. In this study, we used a support vector machine (SVM) whole-brain classification approach to predict future illness course at the individual level from MRI data obtained at the first psychotic episode. Method One hundred patients at their first psychotic episode and 91 healthy controls had an MRI scan. Patients were re-evaluated 6.2 years (s.d.=2.3) later, and were classified as having a continuous, episodic or intermediate illness course. Twenty-eight subjects with a continuous course were compared with 28 patients with an episodic course and with 28 healthy controls. We trained each SVM classifier independently for the following contrasts: continuous versus episodic, continuous versus healthy controls, and episodic versus healthy controls. Results At baseline, patients with a continuous course were already distinguishable, with significance above chance level, from both patients with an episodic course (p=0.004, sensitivity=71, specificity=68) and healthy individuals (p=0.01, sensitivity=71, specificity=61). Patients with an episodic course could not be distinguished from healthy individuals. When patients with an intermediate outcome were classified according to the discriminating pattern episodic versus continuous, 74% of those who did not develop other episodes were classified as episodic, and 65% of those who did develop further episodes were classified as continuous (p=0.035). Conclusions We provide preliminary evidence of MRI application in the individualized prediction of future illness course, using a simple and automated SVM pipeline. When replicated and validated in larger groups, this could enable targeted clinical decisions based on imaging data.

Ethnicity, social disadvantage and psychotic-like experiences in a healthy population based sample

Objective: We sought to investigate the prevalence and social correlates of psychotic‐like experiences in a general population sample of Black and White British subjects.

Volumetric magnetic resonance imaging study of the brain in subjects with sex chromosome aneuploidies

OBJECTIVES Cognitive impairment has been reported in people with sex chromosome aneuploides (SCAs) and it has been proposed that the presence of an extra sex chromosome may have an adverse effect on neurodevelopment. This study examines the hypothesis with structural MRI of the brain. METHODS Thirty two subjects with SCA (XXX (n=12), XYY (n=10), and XXY (n=10)) from a birth cohort study were matched groupwise for age, parental social class, and height with normal controls (13 female, 26 male). Brain MRI , measurements of IQ, and a structured psychiatric interview were performed. RESULTS The XXX females and XXY males had significantly smaller whole brain volumes than controls of the same phenotypic sex (p=0.003 and p⩽0.05 respectively). The XXY group also had bilaterally enlarged lateral ventricles (p⩽0.05). No significant differences were found between the XYY group and controls. IQ scores in all SCA groups were lower than in the control groups. CONCLUSIONS The main result of reduced brain volumes in XXX and XXY subjects, but not in XYY subjects, indicates that the presence of a supernumerary X chromosome has a demonstrable effect on brain development.

Perceptions of disadvantage, ethnicity and psychosis

BACKGROUND People from Black ethnic groups (African-Caribbean and Black African) are more prone to develop psychosis in Western countries. This excess might be explained by perceptions of disadvantage. AIMS To investigate whether the higher incidence of psychosis in Black people is mediated by perceptions of disadvantage. METHOD A population-based incidence and case-control study of first-episode psychosis (Aetiology and Ethnicity in Schizophrenia and Other Psychoses (AESOP)). A total of 482 participants answered questions about perceived disadvantage. RESULTS Black ethnic groups had a higher incidence of psychosis (OR= 4.7, 95% CI 3.1-7.2). After controlling for religious affiliation, social class and unemployment, the association of ethnicity with psychosis was attenuated (OR=3.0, 95% CI 1.6-5.4) by perceptions of disadvantage. Participants in the Black non-psychosis group often attributed their disadvantage to racism, whereas Black people in the psychosis group attributed it to their own situation. CONCLUSIONS Perceived disadvantage is partly associated with the excess of psychosis among Black people living in the UK. This may have implications for primary prevention.