Melanie A. Porter

A meta-analysis of cognitive deficits in first-episode Major Depressive Disorder.

BACKGROUND Recurrent-episode Major Depressive Disorder (MDD) is associated with a number of neuropsychological deficits. To date, less is known about whether these are present in the first-episode. The current aim was to systematically evaluate the literature on first-episode MDD to determine whether cognition may be a feasible target for early identification and intervention. METHODS Electronic database searches were conducted to examine neuropsychological studies in adults (mean age greater than 18 years old) with a first-episode of MDD. Effect sizes were pooled by cognitive domain. Using meta-regression techniques, demographic and clinical factors potentially influencing heterogeneity of neuropsychological outcome were also investigated. RESULTS The 15 independent samples reviewed yielded data for 644 patients with a mean age of 39.36 years (SD=10.21). Significant cognitive deficits were identified (small to medium effect sizes) for psychomotor speed, attention, visual learning and memory, and all aspects of executive functioning. Symptom remission, inpatient status, antidepressant use, age and educational attainment, each significantly contributed to heterogeneity in effect sizes in at least one cognitive domain. LIMITATIONS Reviewed studies were limited by small sample sizes and often did not report important demographic and clinical characteristics of patients. CONCLUSIONS The current meta-analysis was the first to systematically demonstrate reduced neuropsychological functioning in first-episode MDD. Psychomotor speed and memory functioning were associated with clinical state, whereas attention and executive functioning were more likely trait-markers. Demographic factors were also associated with heterogeneity across studies. Overall, cognitive deficits appear to be feasible early markers and targets for early intervention in MDD.

The neuropsychological basis of hypersociability in Williams and Down syndrome

People with Williams syndrome (WS) display indiscriminate approach toward strangers in everyday life. People with Down syndrome (DS) can also do so, but to a lesser degree. Inappropriate approach behavior is also characteristic of people with acquired amygdala damage and people with acquired frontal lobe impairment; given this, the developmental disorder of social approach seen in WS and perhaps also DS might be due to poor emotion recognition (due to abnormal amygdala functioning) or poor control of behavior (due to frontal lobe abnormality). A third account of this developmental disorder of social cognition can be couched in terms of heightened salience for social stimuli. We explored these three hypotheses by testing emotion recognition, social approach and frontal lobe functioning in people with WS and DS. Overall, our results were inconsistent with predictions from the amygdala and social salience hypotheses. In contrast, results from a battery of neuropsychological tasks suggested that abnormal social approach in WS and DS in everyday life is best explained by frontal lobe impairment, in particular, poor response inhibition.

Neuropsychological and socio-occupational functioning in young psychiatric outpatients: A longitudinal investigation

Background Clinical symptoms and neuropsychological deficits are longitudinally associated with functional outcome in chronic psychiatric cohorts. The current study extended these findings to young and early-course psychiatric outpatients, with the aim of identifying cognitive markers that predict later socio-occupational functioning. Methods At baseline, 183 young psychiatric outpatients were assessed. Ninety-three returned for follow-up (M = 21.6 years old; SD = 4.5) with an average re-assessment interval of 21.6 months (SD = 7.0), and primary diagnoses of major depressive disorder (n = 34), bipolar disorder (n = 29), or psychosis (n = 30). The primary outcome measure was cross-validated with various other functional measures and structural equation modelling was used to map out the interrelationships between predictors and later functional outcome. Results Good socio-occupational functioning at follow-up was associated with better quality of life, less disability, current employment and being in a romantic relationship. The final structural equation model explained 47.5% of the variability in functional outcome at follow-up, with baseline neuropsychological functioning (a composite of memory, working memory and attentional switching) the best independent predictor of later functional outcome. Notably, depressive and negative symptoms were only associated with functioning cross-sectionally. Diagnosis at follow-up was not associated with functional outcome. Conclusions Neuropsychological functioning was the single best predictor of later socio-occupational outcome among young psychiatric outpatients. Therefore, framing psychiatric disorders along a neuropsychological continuum is likely to be more useful in predicting functional trajectory than traditional symptom-based classification systems. The current findings also have implications for early intervention utilising cognitive remediation approaches.

Global and Local Processing in Williams Syndrome, Autism, and Down Syndrome: Perception, Attention, and Construction

Global and local processing was studied in Williams Syndrome (WS), autism (AS), and Down Syndrome (DS) using perception, attention, and construction tasks. Past research has suggested an abnormal bias toward global processing in DS and, in contrast, an abnormal local bias in both WS and AS. Until now, no study has investigated whether the local processing bias in WS and AS has a different or similar underlying cause. Findings here suggest a common underlying mechanism, namely a bias in attention toward local processing. Results also indicate a global bias in attention in DS. This study finds no evidence to support predictions of the hierarchical deficit theory (Mottron & Belleville, 1993) as an explanation of hierarchical processing deficits in AS or DS, but does find support for hierarchical deficit theory in a subset of WS individuals. This study finds evidence of cognitive heterogeneity in WS, consistent with Porter and Coltheart (2005).

Cognitive remediation improves memory and psychosocial functioning in first-episode psychiatric out-patients.

Background Cognitive remediation (CR) is an effective treatment for several psychiatric disorders. To date, there have been no published studies examining solely first-episode psychiatric cohorts, despite the merits demonstrated by early intervention CR studies. The current study aimed to assess the effectiveness of CR in patients with a first-episode of either major depression or psychosis. Method Fifty-five patients (mean age = 22.8 years, s.d. = 4.3) were randomly assigned to either CR (n = 28) or treatment as usual (TAU; n = 27). CR involved once-weekly 2-h sessions for a total of 10 weeks. Patients were comprehensively assessed before and after treatment. Thirty-six patients completed the study, and analyses were conducted using an intent-to-treat (ITT) approach with all available data. Results In comparison to TAU, CR was associated with improved immediate learning and memory controlling for diagnosis and baseline differences. Similarly, CR patients demonstrated greater improvements than TAU patients in psychosocial functioning irrespective of diagnosis. Delayed learning and memory improvements mediated the effect of treatment on psychosocial functioning at a marginal level. Conclusions CR improves memory and psychosocial outcome in first-episode psychiatric out-patients for both depression and psychosis. Memory potentially mediated the functional gains observed. Future studies need to build on the current findings in larger samples using blinded allocation and should incorporate longitudinal follow-up and assessment of potential moderators (e.g. social cognition, self-efficacy) to examine sustainability and the precise mechanisms of CR effects respectively.

An Unusual attraction to the eyes in Williams-Beuren syndrome : a manipulation of facial affect while measuring face scanpaths

Introduction. This study aimed to investigate face scanpaths and emotion recognition in Williams-Beuren syndrome (WBS) and whether: (1) the eyes capture the attention of WBS individuals faster than typically developing mental age-matched controls; (2) WBS patients spend abnormally prolonged periods of time viewing the eye region; and (3) emotion recognition skills or eye gaze patterns change depending on the emotional valance of the face. Methods. Visual scanpaths were recorded while 16 WBS patients and 16 controls passively viewed happy, angry, fearful, and neutral faces. Emotion recognition was subsequently measured. Results. The eyes did not capture the attention of WBS patients faster than controls, but once WBS patients attended to the eyes, they spent significantly more time looking at this region. Unexpectedly, WBS patients showed an impaired ability to recognise angry faces, but face scanpaths were similar across the different facial expressions. Conclusions. Findings suggest that face processing is atypical in WBS and that emotion recognition and eye gaze abnormalities in WBS are likely to be more complex than previously thought. Findings highlight the need to develop remediation programmes to teach WBS patients how to explore all facial features, enhancing their emotion recognition skills and “normalising” their social interactions.

I see happy people: Attention bias towards happy but not angry facial expressions in Williams syndrome.

Introduction. Observations of behaviour and research using eyetracking technology have shown that individuals with Williams syndrome (WS) pay an unusual amount of attention to other peoples faces. The present research examines whether this attention to faces is moderated by the valence of emotional expression. Method. Sixteen participants with WS aged between 13 and 29 years (mean = 19 years 9 months) completed a dot-probe task in which pairs of faces displaying happy, angry, and neutral expressions were presented. The performance of the WS group was compared to two groups of typically developing control participants, individually matched to the participants in the WS group on either chronological age or mental age. General mental age was assessed in the WS group using the Woodcock-Johnson Test of Cognitive Ability–Revised (WJ-COG-R; Woodcock & Johnson, 1989/1990). Results. Compared to both control groups, the WS group exhibited a greater attention bias for happy faces. In contrast, no between-group differences in bias for angry faces were obtained. Conclusions. The results are discussed in relation to recent neuroimaging findings and the hypersocial behaviour that is characteristic of the WS population.

Psychopathology in Williams Syndrome: The Effect of Individual Differences Across the Life Span

This research aimed to comprehensively explore psychopathology in Williams syndrome (WS) across the life span and evaluate the relationship between psychopathology and age category (child or adult), gender, and cognitive ability. The parents of 50 participants with WS, ages 6–50 years, were interviewed using the Schedule for Affective Disorders and Schizophrenia for School-Age Children. The prevalence of a wide range of Axis I Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric Association, 1994) disorders was assessed. In addition to high rates of anxiety and attention-deficit/hyperactivity disorder (38% and 20%, respectively), 14% of our sample met criteria for a Depressive Disorder and 42% of participants were not experiencing any significant psychopathological difficulties. There was some evidence for different patterns of psychopathology between children and adults with WS and between males and females. These relationships were largely in keeping with those found in the typically developing population, thus supporting the validity of applying theory and treatment approaches for psychopathology in the typically developing population to WS.

Self-control in honeybees.

Self-control means choosing a large delayed reward over a small immediate reward; impulsiveness is its opposite. The metabolic hypothesis states that the amount of self-control across species correlates negatively with metabolic rate (Tobin & Logue, 1994). Foraging honeybees have high metabolic rates; the metabolic hypothesis would predict little self-control in bees. But foraging bees work for the longterm good of their hive, conditions that seem to require self-control. In three experiments, we gave bees the choice between (1) a sweeter delayed reward and a less sweet immediate reward and (2) a large delayed reward and a small immediate reward. Bees showed much self-control, inconsistent with the metabolic hypothesis.

Social Approach in Pre-School Children with Williams Syndrome: The Role of the Face.

BACKGROUND Indiscriminate social approach behaviour is a salient aspect of the Williams syndrome (WS) behavioural phenotype. The present study examines approach behaviour in pre-schoolers with WS and evaluates the role of the face in WS social approach behaviour. METHOD Ten pre-schoolers with WS (aged 3-6 years) and two groups of typically developing children, matched to the WS group on chronological or mental age, participated in an observed play session. The play session incorporated social and non-social components including two components that assessed approach behaviour towards strangers; one in which the strangers face could be seen and one in which the strangers face was covered. RESULTS In response to the non-social aspects of the play session, the WS group behaved similarly to both control groups. In contrast, the pre-schoolers with WS were significantly more willing than either control group to engage with a stranger, even when the strangers face could not be seen. CONCLUSION The findings challenge the hypothesis that an unusual attraction to the face directly motivates social approach behaviour in individuals with WS.