Kathryn McCabe

Australian schizophrenia research bank: a database of comprehensive clinical, endophenotypic and genetic data for aetiological studies of schizophrenia

Objective: This article describes the establishment of the Australian Schizophrenia Research Bank (ASRB), which operates to collect, store and distribute linked clinical, cognitive, neuroimaging and genetic data from a large sample of people with schizophrenia and healthy controls. Method: Recruitment sources for the schizophrenia sample include a multi-media national advertising campaign, inpatient and community treatment services and non-government support agencies. Healthy controls have been recruited primarily through multi-media advertisements. All participants undergo an extensive diagnostic and family history assessment, neuropsychological evaluation, and blood sample donation for genetic studies. Selected individuals also complete structural MRI scans. Results: Preliminary analyses of 493 schizophrenia cases and 293 healthy controls are reported. Mean age was 39.54 years (SD = 11.1) for the schizophrenia participants and 37.38 years (SD = 13.12) for healthy controls. Compared to the controls, features of the schizophrenia sample included a higher proportion of males (cases 65.9%; controls 46.8%), fewer living in married or de facto relationships (cases 16.1%; controls 53.6%) and fewer years of education (cases 13.05, SD = 2.84; controls 15.14, SD = 3.13), as well as lower current IQ (cases 102.68, SD = 15.51; controls 118.28, SD = 10.18). These and other sample characteristics are compared to those reported in another large Australian sample (i.e. the Low Prevalence Disorders Study), revealing some differences that reflect the different sampling methods of these two studies. Conclusion: The ASRB is a valuable and accessible schizophrenia research facility for use by approved scientific investigators. As recruitment continues, the approach to sampling for both cases and controls will need to be modified to ensure that the ASRB samples are as broadly representative as possible of all cases of schizophrenia and healthy controls.

Visual scanning of faces in 22q11.2 deletion syndrome: Attention to the mouth or the eyes?

Previous research demonstrates that people with 22q11.2 deletion syndrome (22q11DS) have social and interpersonal skill deficits. However, the basis of this deficit is unknown. This study examined, for the first time, how people with 22q11DS process emotional face stimuli using visual scanpath technology. The visual scanpaths of 17 adolescents and age/gender matched healthy controls were recorded while they viewed face images depicting one of seven basic emotions (happy, sad, surprised, angry, fear, disgust and neutral). Recognition accuracy was measured concurrently. People with 22q11DS differed significantly from controls, displaying visual scanpath patterns that were characterised by fewer fixations and a shorter scanpath length. The 22q11DS group also spent significantly more time gazing at the mouth region and significantly less time looking at eye regions of the faces. Recognition accuracy was correspondingly impaired, with 22q11DS subjects displaying particular deficits for fear and disgust. These findings suggest that 22q11DS is associated with a maladaptive visual information processing strategy that may underlie affect recognition accuracy and social functioning deficits in this group.

Is theory of mind related to social dysfunction and emotional problems in 22q11.2 deletion syndrome (velo-cardio-facial syndrome)?

Social dysfunction is intrinsically involved in severe psychiatric disorders such as depression and psychosis and linked with poor theory of mind. Children with 22q11.2 deletion syndrome (22q11DS, or velo-cardio-facial syndrome) have poor social competence and are also at a particularly high risk of developing mood (40%) and psychotic (up to 30%) disorders in adolescence and young adulthood. However, it is unknown if these problems are associated with theory of mind skills, including underlying social-cognitive and social-perceptual mechanisms. The present cross-sectional study included classic social-cognitive false-belief and mentalising tasks and social-perceptual face processing tasks. The performance of 50 children with 22q11DS was compared with 31 age-matched typically developing sibling controls. Key findings indicated that, while younger children with 22q11DS showed impaired acquisition of social-cognitive skills, older children with 22q11DS were not significantly impaired compared with sibling controls. However, children with 22q11DS were found to have social-perceptual deficits, as demonstrated by difficulties in matching faces on the basis of identity, emotion, facial speech and gaze compared with sibling controls. Furthermore, performance on the tasks was associated with age, language ability and parentally rated social competence and emotional problems. These results are discussed in relation to the importance of a better delineation of social competence in this population.

Relationship between childhood adversity and clinical and cognitive features in schizophrenia.

Childhood adversity is associated with elevated risk for a wide range of adult psychiatric disorders, and has significant and sustained negative effects on adult behavioural and social functioning. Elevated rates of childhood adversity have been reported for people with a diagnosis of schizophrenia. The aim of the present study was to assess rates of retrospectively reported childhood adversity among adults with schizophrenia and to examine the relationship between childhood adversity and clinical and cognitive features. Data were available for 408 schizophrenia participants and 267 healthy control participants recruited through the Australian Schizophrenia Research Bank (ASRB). History of childhood adversity was obtained using the Childhood Adversity Questionnaire (CAQ). A five-factor solution was identified from the CAQ. Schizophrenia participants reported experiencing more childhood adversities than controls. In both groups, those reporting childhood adversity were more likely to be female and older. Among participants with schizophrenia, positive symptom severity and fewer years of education were associated with childhood adversity. Lower IQ scores and personality traits were associated with reporting a greater number of childhood adversities and with adversity sub-types of abusive, neglectful and dysfunctional parenting. The rate of childhood adversity reported in this sample was high which suggests greater exposure to adverse childhood events among participants with schizophrenia in comparison with healthy controls. We identified unique groups amongst CAQ items that provided a salient framework from which to investigate the connection between childhood adversity and clinical and cognitive features.

Visual scanpath abnormalities in 22q11.2 deletion syndrome: is this a face specific deficit?

People with 22q11.2 deletion syndrome (22q11DS) have deficits in face emotion recognition. However, it is not known whether this is a deficit specific to faces, or represents maladaptive information processing strategies to complex stimuli in general. This study examined the specificity of face emotion processing deficits in 22q11DS by exploring recognition accuracy and visual scanpath performance to a Faces task compared to a Weather Scene task. Seventeen adolescents with 22q11DS (11=females, age=17.4) and 18 healthy controls (11=females, age=17.7) participated in the study. People with 22q11DS displayed an overall impoverished scanning strategy to face and weather stimuli alike, resulting in poorer accuracy across all stimuli for the 22q11DS participants compared to controls. While the control subjects altered their information processing in response to faces, a similar change was not present in the 22q11DS group indicating different visual scanpath strategies to identify category within each of the tasks, of which faces appear to represent a particularly difficult subcategory. To conclude, while this study indicates that people with 22q11DS have a general visual processing deficit, the lack of strategic change between tasks suggest that the 22q11DS group did not adapt to the change in stimuli content as well as the controls, indicative of cognitive inflexibility rather than a face specific deficit.

Differential susceptibility to performance degradation across categories of facial emotion - a model confirmation

Patients with a number of psychiatric and neuropathological conditions demonstrate problems in recognising facial expressions of emotion. Research indicating that patients with schizophrenia perform more poorly in the recognition of negative valence facial stimuli than positive valence stimuli has been interpreted as evidence of a negative emotion specific deficit. An alternate explanation rests in the psychometric properties of the stimulus materials. This model suggests that the pattern of impairment observed in schizophrenia may reflect initial discrepancies in task difficulty between stimulus categories, which are not apparent in healthy subjects because of ceiling effects. This hypothesis is tested, by examining the performance of healthy subjects in a facial emotion categorisation task with three levels of stimulus resolution. Results confirm the predictions of the model, showing that performance degrades differentially across emotion categories, with the greatest deterioration to negative valence stimuli. In the light of these results, a possible methodology for detecting emotion specific deficits in clinical samples is discussed.

Social cognition dysfunction in adolescents with 22q11.2 deletion syndrome (velo-cardio-facial syndrome): relationship with executive functioning and social competence/functioning.

BACKGROUND Social difficulties are often noted among people with intellectual disabilities. Children and adults with 22q.11.2 deletion syndrome (22q11DS) often have poorer social competence as well as poorer performance on measures of executive and social-cognitive skills compared with typically developing young people. However, the relationship between social functioning and more basic processes of social cognition and executive functioning are not well understood in 22q11DS. The present study examined the relationship between social-cognitive measures of emotion attribution and theory of mind with executive functioning and their contribution to social competence in 22q11DS. METHOD The present cross-sectional study measured social cognition and executive performance of 24 adolescents with 22q11DS compared with 27 age-matched typically developing controls. Social cognition was tested using the emotion attribution task (EAT) and a picture sequencing task (PST), which tested mentalising (false-belief), sequencing, cause and effect, and inhibition. Executive functioning was assessed using computerised versions of the Tower of London task and working memory measures of spatial and non-spatial ability. Social competence was also assessed using the parent-reported Strengths and Difficulties Questionnaire. RESULTS Adolescents with 22q11DS showed impaired false-belief, emotion attribution and executive functioning compared with typically developing control participants. Poorer performance was reported on all story types in the PST, although, patterns of errors and response times across story types were similar in both groups. General sequencing ability was the strongest predictor of false-belief, and performance on the false-belief task predicted emotion attribution accuracy. Intellectual functioning, rather than theory of mind or executive functioning, predicted social competence in 22q11DS. CONCLUSIONS Performance on social-cognitive tasks of theory of mind indicate evidence of a general underlying dysfunction in 22q11DS that includes executive ability to understand cause and effect, to logically reason about social scenarios and also to inhibit responses to salient, but misleading cues. However, general intellectual ability is closely related to actual social competence suggesting that a generalised intellectual deficit coupled with more specific executive impairments may best explain poor social cognition in 22q11DS.

Divergent Patterns of Social Cognition Performance in Autism and 22q11.2 Deletion Syndrome (22q11DS)

Individuals with developmental disorders frequently report a range of social cognition deficits including difficulties identifying facial displays of emotion. This study examined the specificity of face emotion processing deficits in adolescents with either autism or 22q11DS compared to typically developing (TD) controls. Two tasks (face emotion recognition and weather scene recognition) were used to explore group differences in visual scanpath strategy and concurrent recognition accuracy. For faces, the autism and 22q11DS groups demonstrated lower emotion recognition accuracy and fewer fixations compared to the TD group. Individuals with autism demonstrated fewer fixations to some weather scene stimuli compared to 22q11DS and TD groups, yet achieved a level of recognition accuracy comparable to the TD group. These findings provide evidence for a divergent pattern of social cognition dysfunction in autism and 22q11DS.

Investigating the Lived Experience of Recovery in People Who Hear Voices

Although there is evidence of both clinical and personal recovery from distressing voices, the process of recovery over time is unclear. Narrative inquiry was used to investigate 11 voice-hearers’ lived experience of recovery. After a period of despair/exhaustion, two recovery typologies emerged: (a) turning toward/empowerment, which involved developing a normalized account of voices, building voice-specific skills, integration of voices into daily life, and a transformation of identity, and (b) turning away/protective hibernation, which involved harnessing all available resources to survive the experience, with the importance of medication in recovery being emphasized. Results indicated the importance of services being sensitive and responsive to a person’s recovery style at any given time and their readiness for change. Coming to hold a normalized account of voice-hearing and the self and witnessing of preferred narratives by others were essential in the more robust turning toward recovery typology.

Pre-pulse inhibition and antisaccade performance indicate impaired attention modulation of cognitive inhibition in 22q11.2 deletion syndrome (22q11DS)

Background22q11.2 deletion syndrome (22q11DS) is associated with a number of physical anomalies and neuropsychological deficits including impairments in executive and sensorimotor function. It is estimated that 25% of children with 22q11DS will develop schizophrenia and other psychotic disorders later in life. Evidence of genetic transmission of information processing deficits in schizophrenia suggests performance in 22q11DS individuals will enhance understanding of the neurobiological and genetic substrates associated with information processing. In this report, we examine information processing in 22q11DS using measures of startle eyeblink modification and antisaccade inhibition to explore similarities with schizophrenia and associations with neurocognitive performance.MethodsStartle modification (passive and active tasks; 120- and 480-ms pre-pulse intervals) and antisaccade inhibition were measured in 25 individuals with genetically confirmed 22q11DS and 30 healthy control subjects.ResultsIndividuals with 22q11DS exhibited increased antisaccade error as well as some evidence (trend-level effect) of impaired sensorimotor gating during the active condition, suggesting a dysfunction in controlled attentional processing, rather than a pre-attentive dysfunction using this paradigm.ConclusionsThe findings from the present study show similarities with previous studies in clinical populations associated with 22q11DS such as schizophrenia that may indicate shared dysfunction of inhibition pathways in these groups.