Alasdair Vance | The University of Melbourne University (original) (raw)

Papers by Alasdair Vance

International Journal of Mental Health and Addiction, 2018

In the field of psychopathology, there is high comorbidity between different disorders. Tradition... more In the field of psychopathology, there is high comorbidity between different disorders. Traditionally, support for two broad correlated dimensions of internalizing and externalizing symptoms has consistently emerged for children and adolescents. To date, oblique 2 and 3 first-order factor models (factors for externalizing and internalizing, and fear, distress, and externalizing) and bi-factor models with the corresponding two and three group factors have been suggested for common internalizing and eternalizing child and adolescent disorders. The present study used confirmatory factor analyses to examine the relative support for these models in adolescents (≥ 12 to 18 years; N = 866) and children (6 to < 12 years; N = 1233) and the reliability and convergent and divergent validities of the psychopathology factor (P-factor) and group factors in the optimum bi-factor model. All participants were from a clinic and underwent Diagnostic and Statistical Manual of Mental Disorders, 4th Edition clinical diagnosis. The findings showed that the bi-factor model with two group factors (internalizing and externalizing) was the optimum model for both children and adolescents. For both groups, findings showed relatively higher reliability for the P-factor than the group factors, although the externalizing group factor showed substantial reliability in adolescents, and both the externalizing and internalizing group factors also showed substantial reliability in children. The factors of the optimum bi-factor model also showed good convergent and discriminant validities. The implications for theory and clinical and research practice related to psychopathology are discussed.

Item Response Theory Analysis of the Anxiety and Mood Disorders in Clinic-Referred Children

Assessment, 2016

There is evidence that the major anxiety and depressive disorders could reflect a single underlyi... more There is evidence that the major anxiety and depressive disorders could reflect a single underlying internalization factor. For a group of 1,031 clinic-referred children, the study examined support for this factor, and used the two-parameter logistic model to examine the item response theory properties of the disorders in this factor. For the set of anxiety and depressive disorders, confirmatory factor analysis supported a one-factor model. The two-parameter logistic model analysis indicated that all the internalizing disorders in this factor were strong discriminators of the internalizing dimension. Also, they measured more of the internalizing dimension and with more precision in the upper half of the trait continuum. There was also support for the convergent validity of the internalizing dimension, in that it had large-to-medium effect size correlations with internalizing scores of other measures. The implications of the findings for clinical practice and clinical classification ...

Psychiatry research, Aug 20, 2016

Attention-deficit/hyperactivity disorder (ADHD) has reliably been associated with global grey mat... more Attention-deficit/hyperactivity disorder (ADHD) has reliably been associated with global grey matter reductions but local alterations are largely inconsistent with perhaps the exception of the caudate nucleus. The aim of this study was to examine local and global brain volume differences between typically developing children (TD) and children with a diagnosis of ADHD. We also addressed whether these parameters would differ between children with the ADHD-combined type (ADHD-C) and those with the ADHD-inattentive type (ADHD-I). Using an ROI approach caudate volume differences were also examined. 79 boys between the ages of 8 and 17 participated in the study. Of those 33 met diagnostic criteria for the ADHD-C and 15 for the ADHD-I subtype. 31 boys were included in the TD group. Structural magnetic resonance imaging data were analysed using voxel-based morphometry. The ADHD group had significantly lower global and local grey matter volumes within clusters in the bilateral frontal, right...

Current Attention Disorders Reports, 2009

Attention-defi cit/hyperactivity disorder (ADHD) and dysthymic disorder (DD) are common childhood... more Attention-defi cit/hyperactivity disorder (ADHD) and dysthymic disorder (DD) are common childhood psychiatric disorders that have a greater-than-chance association. To date, their relationship has not been systematically examined despite their frequent co-occurrence in children and adolescents referred to clinical health services. This article defi nes ADHD and DD, reviews their characteristics, and outlines the emerging evidence from phenomenological and cognitive neuroscience studies regarding their association. ADHD and, separately, DD are signifi cant drivers for oppositional defi ant disorder symptoms in children and adolescents. ADHD and DD both have elevated levels of neurological subtle signs, spatial working memory defi cits, and right frontal-striatal-parietal underactivation compared with healthy control participants. ADHD and DD both also have elevated levels of parental psychopathology, with the comorbid group having signifi cantly higher levels than those with ADHD or DD alone. We explore the clinical implications of these fi ndings.

Differential Diagnosis and Comorbid ADHD in Childhood

Handbook of Child and Adolescent Anxiety Disorders, 2011

Anxiety disorders and Attention Deficit Hyperactivity Disorder (ADHD) are both common conditions ... more Anxiety disorders and Attention Deficit Hyperactivity Disorder (ADHD) are both common conditions in children and adolescents. Further, there is a known significant association between them, evident in epidemiological and clinical studies (Anderson, Williams, McGee, &amp;amp;amp;amp;amp;amp;amp;amp;amp; Silva, 1987; Biederman, Newcorn, &amp;amp;amp;amp;amp;amp;amp;amp;amp; Sprich, 1991; Jensen et al., 2001). This chapter explores how ADHD affects the diagnosis, clinical presentation, assessment and treatment of

Psychopharmacology, 2012

Pharmacological evidence suggests the importance of noradrenergic and other monoaminergic neurotr... more Pharmacological evidence suggests the importance of noradrenergic and other monoaminergic neurotransmitters in the aetiology and treatment of attention deficit hyperactivity disorder (ADHD). Until recently, the genes of the noradrenergic pathway were not intensively investigated in ADHD compared to dopaminergic and serotonergic candidates. In this study, 91 SNP markers of 14 noradrenergic genes (an average density of one SNP per 4.5 kbp) were examined in ADHD samples from Ireland and Australia. Although suggestive evidence of association (nominal p≤0.05) with the genes SLC6A2, ADRA1A, ADRA1B and ADRA2B was observed, none remained significant after permutation adjustments. In contrast, haplotype analyses demonstrated a significant association between ADHD and a SLC6A2 haplotype comprising the markers rs36009, rs1800887, rs8049681, rs2242447 and rs9930182 (χ 2 09.39, p-corrected00.019, OR01.51). A rare ADRA1B haplotype made of six SNPs (rs2030373, rs6884105, rs756275, rs6892282, rs6888306 and rs13162302) was also associated (χ 2 07.79, p-corrected00.042 OR02.74) with the disorder. These findings provide evidence of a contribution of the noradrenaline system to the genetic aetiology of ADHD. The observed haplotype association signals may be driven by as yet unidentified functional risk variants in or around the associated regions. Functional genomic analysis is warranted to determine the biological mechanism of the observed association.

PLoS ONE, 2013

Background: The Coloboma mouse carries a ,2 cM deletion encompassing the SNAP25 gene and has a hy... more Background: The Coloboma mouse carries a ,2 cM deletion encompassing the SNAP25 gene and has a hyperactive phenotype similar to that of ADHD. Such mice are 3 fold more active compared to their control littermates. Genetic association studies support a role for allelic variants of the human SNAP25 gene in predisposing to ADHD. Methods/Principal Findings: We performed association analysis across the SNAP25 gene in 1,107 individuals (339 ADHD trios). To assess the functional relevance of the SNAP25-ADHD associated allele, we performed quantitative PCR on postmortem tissue derived from the inferior frontal gyrus of 89 unaffected adults. Significant associations with the A allele of SNP rs362990 (x 2 = 10, p-corrected = 0.019, OR = 1.5) and three marker haplotypes (rs6108461, rs362990 and rs362998) were observed. Furthermore, a significant additive decrease in the expression of the SNAP25 transcript as a function of the risk allele was also observed. This effect was detected at the haplotype level, where increasing copies of the ADHD-associated haplotype reduced the expression of the transcript. Conclusions: Our data show that DNA variation at SNAP25 confers risk to ADHD and reduces the expression of the transcript in a region of the brain that is critical for the regulation of attention and inhibition.

Pediatric Blood & Cancer, 2009

PAT2.0 scores at T2. Conclusions. Findings support the external validity of the PAT2.0 as a psych... more PAT2.0 scores at T2. Conclusions. Findings support the external validity of the PAT2.0 as a psychosocial screener. Mothers' and fathers' ratings of risk are similar; however, multi-informant use of the PAT2.0 may be clinically useful. Psychosocial risk, as measured by the PAT2.0, is a relatively stable construct over the first months of treatment and is independent of treatment intensity.

Olfactory Impairments in Child Attention-Deficit/Hyperactivity Disorder

The Journal of Clinical Psychiatry, 2008

This study compared unilateral olfactory identification abilities in children with and without at... more This study compared unilateral olfactory identification abilities in children with and without attention-deficit/hyperactivity disorder (ADHD) and evaluated the utility of the University of Pennsylvania Smell Identification Test (UPSIT) as a potential screening tool for the diagnosis of ADHD. Subjects comprised 44 children with DSM-IV ADHD (aged 7-16 years) from 2 Melbourne, Australia, hospital outpatient clinics and 44 healthy children matched for age and sex. The children were assessed from March 2004 to October 2004 for olfactory identification ability using the UPSIT, and behavioral data were gathered using the Rowe Behavioral Rating Inventory. Background and demographic data were also obtained through hospital records and parental interview. Children with ADHD demonstrated significantly poorer olfactory identification ability compared to healthy controls (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .01). A significant right nostril advantage for smell identification was evident in the control group (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .01), whereas significant right nostril impairment was evident among the children with ADHD (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .01). The results provide the first evidence of olfactory identification deficits in children with ADHD. As such deficits implicate orbitofrontal regions, this finding is consistent with previous reports of prefrontal compromise in children with ADHD.

Journal of Child Psychology and Psychiatry, 2009

Background: Evidence for a selective attention abnormality in children with attention deficit hy... more Background: Evidence for a selective attention abnormality in children with attention deficit hyperactivity disorder (ADHD) has been hard to identify using conventional methods from cognitive science. This study tested whether the presence of selective attention abnormalities in ADHD may vary as a function of perceptual load and target lateralisation. Given evidence of right‐hemisphere dysfunction in ADHD we predicted increased interference effects for right, but not left‐sided target displays, particularly under low perceptual load.Method: Fourteen children with ADHD‐C and 14 typically developing children were tested on a modified flanker task under low and high perceptual load. We also sought evidence for our hypothesis in a re‐analysis of an independent data set (42 ADHD; 34 typically developing) in which load effects on selective attention in ADHD were previously examined (Huang‐Pollock, Nigg, & Carr, 2005).Results: As predicted, all children showed evidence of greater interf...

Journal of Abnormal Child Psychology, 2013

Examination of spatial working memory performance in children and adolescents with Attention Defi... more Examination of spatial working memory performance in children and adolescents with Attention Deficit Hyperactivity Disorder, combined type (ADHD-CT) and anxiety Spatial working memory (SWM) is known to be impaired in children with ADHD-CT, whether anxiety is present or not. Yet, it remains unclear whether anxiety disorders add to the SWM impairments evident in ADHD-CT and whether these findings extend into adolescents with ADHD-CT and anxiety. Further, it is not yet known whether children and adolescents with carefully defined anxiety disorders alone, demonstrate SWM deficits. This study explored the association of SWM and its strategy and spatial span components in carefully defined children and adolescents (age 6-16 years) with ADHD-CT alone (N=163; 14% female), ADHD-CT and anxiety (N=243; 23% female), anxiety disorders alone (N=69; 25% female) compared to ageand gender-matched healthy control participants (N=116; 19% female). The relationship between SWM and its strategy and span components and core ADHD-CT symptoms and anxiety symptoms were also examined. There was no evidence of an additive effect of ADHD and anxiety on SWM, strategy and spatial span deficits. But, anxiety disorders alone were associated with impaired SWM and span performance compared to healthy control participants. In contrast, strategy did not differ between children and adolescents with anxiety disorders alone and healthy control participants, suggesting that with anxiety span is the most affected component. Further, these findings were age-independent. This study concurs with and extends current influential models about the cognitive effects of anxiety on performance in the setting of ADHD-CT. Clinical implications and future research directions are discussed.

Journal of Abnormal Child Psychology, 2008

The two-parameter logistic model (2PLM) was used to evaluate the psychometric properties of the i... more The two-parameter logistic model (2PLM) was used to evaluate the psychometric properties of the inattention (IA) and hyperactivity/impulsivity (HI) symptoms. Method: To accomplish this, parents and teachers completed the Disruptive Behavior Rating Scale (DBRS) for a group of 934 primary school-aged children. Results: The results for the discrimination parameters showed that all the IA and HI symptoms for both groups of respondents were generally good for discriminating those with and without IA and HI, respectively. For virtually all symptoms, their threshold values showed endorsement of the symptoms when the underlying trait levels were at least 1 to 1.5 SD above the mean. The item information function values for most symptoms indicated reasonable reliability from around the mean trait levels to moderately high trait levels. Conclusion: These findings indicate good discrimination and reliability for parent and teacher ratings of the DBRS for identifying children with relatively high levels of the ADHD symptoms.

Genetics of cognitive deficits in ADHD: clues for novel treatment methods

Expert Review of Neurotherapeutics, 2008

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent disorder of childhood with a stron... more Attention-deficit/hyperactivity disorder (ADHD) is a prevalent disorder of childhood with a strong genetic contribution. Recently there has been a massive increase in research across multiple fronts, including genetics, neuropsychology and neuroimaging, with impressive gains made. Here, we review the extant literature on the genetic correlates of cognitive deficits in ADHD, focusing on deficits of sustained attention, heightened reaction-time variability and asymmetries of directed spatial attention. The new era of multidisciplinary research means that links can be forged across multiple levels (e.g., gene-cognition) with potentially important implications for treatment. In this review, we highlight how gene-cognition linkages in ADHD might be profitably used to suggest novel approaches to monitoring stimulant-medication responses, as well as strategies for targeting cognitive remediation techniques towards particular subgroups of children and adults with ADHD.

Contextual abnormalities of saccadic inhibition in children with attention deficit hyperactivity disorder

Experimental Brain Research, 2001

Abnormalities of executive function are observed consistently in children with attention-deficit ... more Abnormalities of executive function are observed consistently in children with attention-deficit hyperactivity disorder (ADHD), and it is hypothesised that these arise because of disruption to a behavioural inhibition system. Executive and inhibitory functions were compared between unmedicated and medicated children with ADHD (combined type), age-matched healthy children and healthy adults. Executive functions were measured using a test of spatial working memory shown previously to be sensitive to ADHD and to stimulant medication. Inhibitory functions were measured using an ocular motor paradigm that required individuals to use task context to control the release of fixation. Context was set according to the probability that a target would appear at either of the two locations. In one block, targets appeared on 80% of trials. In the other block, targets appeared on 20% of trials. The ability to control the release of fixation was inferred from the fixation offset effect (FOE), or the difference in saccade latency when the current fixation is offset 200 ms prior to the onset of the saccade target (gap condition), compared with when there is no offset (overlap condition). Although the healthy children made more errors on the spatial working memory task than the healthy adults, there was no difference between the two groups in their ability to control fixation using context. Both showed a larger FOE when target probability was low. As expected, the unmedicated ADHD group made more errors on the spatial working memory test than the healthy children, although spatial working memory performance was normal in the medicated ADHD group. However, both the unmedicated and medicated ADHD groups were unable to modulate the FOE according to context, and this was due to their inability to voluntarily inhibit saccades when there was a low target probability. These data suggest that the context-based modulation of fixation release is not controlled by the same systems that control executive function. Furthermore, deficits in executive function and inhibitory control appear independent in children with ADHD.

Differences in motor imagery between children with developmental coordination disorder with and without the combined type of ADHD

Developmental Medicine & Child Neurology, 2008

Crisis, 2012

Background: In children and adolescents with a depressive disorder, predicting who will also go o... more Background: In children and adolescents with a depressive disorder, predicting who will also go on to exhibit suicide-related behaviors (SRBs), including suicide attempt or self-harm, is a key challenge facing clinicians. Aims: To investigate the relative contributions of depressive disorder severity, hopelessness, family dysfunction, and perceived social support to the risk of suicide-related behaviors. Methods: This was a cross-sectional study of a group of 10–16-year-olds with major depressive disorders and dysthymic disorder. Results: Child-rated depressive disorder symptom severity emerged as the greatest predictor of risk. Hopelessness and family dysfunction were also significant predictors of SRBs. In combination these variables were strong predictors, accounting for 66% of the variance. This is a cross-sectional study design, rather than longitudinal, therefore risk prediction over time was not possible. Conclusions: Understanding the child and adolescents depressive disorde...

Brain and Cognition, 2003

In this study we report the results of two experiments on visual attention conducted with patient... more In this study we report the results of two experiments on visual attention conducted with patients with early-onset schizophrenia. These experiments investigated the effect of irrelevant spatial-scale information upon the processing of relevant spatial-scale information, and the ability to shift the spatial scale of attention, across consecutive trials, between different levels of the hierarchical stimulus. Twelve patients with early-onset schizophrenia and matched controls performed local-global tasks under: (1) directed attention conditions with a consistency manipulation and (2) divided-attention conditions. In the directed-attention paradigm, the early-onset patients exhibited the normal patterns of global advantage and interference, and were not unduly affected by the consistency manipulation. Under divided-attention conditions, however, the early-onset patients exhibited a local-processing deficit. The source of this local processing deficit lay in the prolonged reaction time to local targets, when these had been preceded by a global target, but not when preceded by a local target. These findings suggest an impaired ability to shift the spatial scale of attention from a global to a local spatial scale in early-onset schizophrenia.

Randomized Double-Blind Multicentre Placebo-Controlled Clinical Trial of the Clonidine Adhesive Patch for the Treatment of Tic Disorders

Australian & New Zealand Journal of Psychiatry, 2008

Objective: The aim of the present study was to evaluate the therapeutic effectiveness and safety ... more Objective: The aim of the present study was to evaluate the therapeutic effectiveness and safety of the clonidine adhesive patch in treating tic disorders. Method: A total of 437 patients, who met Chinese Classification of Mental Disorders–third edition diagnostic criteria for transient tic disorder (5%), chronic motor or vocal tic disorder (40%) or Tourette disorder (55%), aged 6–18years, were divided randomly into an active treatment group and a clinical control group. Participants in the active treatment group were treated with a clonidine adhesive patch and participants in the clinical control group with a placebo adhesive patch for 4weeks. The dosage of the clonidine adhesive patch was 1.0mg, 1.5mg or 2.0mg per week, depending on each participant's bodyweight. Participants whose Yale Global Tic Severity Scale (YGTSS) score decreased <30% and Clinical Global Impression score was ≥4 by the end of week 3 were withdrawn from the trial. Results: After 4 weeks of treatment the...

Characteristics of Parent- and Child-Reported Anxiety in Psychostimulant Medication Naïve, Clinically Referred Children with Attention Deficit Hyperactivity Disorder, Combined Type (ADHD-CT)

Australian & New Zealand Journal of Psychiatry, 2002

Objective: Anxiety is a frequent comorbid condition in referred primary school-age children with ... more Objective: Anxiety is a frequent comorbid condition in referred primary school-age children with attention deficit hyperactivity disorder, combined type (ADHD-CT), yet there has been relatively little systematic research of the nature of this comorbid anxiety. We describe the characteristics of parent-reported child anxiety disorders and child-reported anxiety disorders in primary school-age children with ADHD-CT. Method: A cross-sectional study of 75 clinically-referred psychostimulant medication naïve children with ADHD-CT examining separately parent and child reports of anxiety, defined categorically and dimensionally. A two-year follow up of 12 children with parent-reported child anxiety and 12 children with child-reported anxiety was also completed. Results: There was no significant association between the child and parent reports of anxiety. Generalized anxiety disorder (GAD), separation anxiety disorder (SAD), specific phobia (SpPh) and social phobia (SoPh) were the most comm...