Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Hannah Dickson is active.

Publication


Featured researches published by Hannah Dickson.


Psychological Medicine | 2012

Meta-analyses of cognitive and motor function in youth aged 16 years and younger who subsequently develop schizophrenia

Hannah Dickson; Kristin R. Laurens; Alexis E. Cullen; Sheilagh Hodgins

BACKGROUND Previous reviews have reported cognitive and motor deficits in childhood and adolescence among individuals who later develop schizophrenia. However, these reviews focused exclusively on studies of individuals with affected relatives or on population/birth cohorts, incorporated studies with estimated measures of pre-morbid intelligence, or included investigations that examined symptomatic at-risk participants or participants 18 years or older. Thus, it remains unclear whether cognitive and motor deficits constitute robust antecedents of schizophrenia. Meta-analyses were conducted on published studies that examined cognitive or motor function in youth aged 16 years or younger who later developed schizophrenia or a schizophrenia spectrum disorder (SSD) and those who did not. METHOD Twenty-three studies fulfilled the following inclusion criteria: (1) written in English; (2) prospective investigations of birth or genetic high-risk cohorts, or follow-back investigations of population samples; (3) objective measures of cognitive or motor performance at age 16 or younger; (4) results provided for individuals who did and who did not develop schizophrenia/SSD later in life; and (5) sufficient data to calculate effect sizes. Four domains of function were examined: IQ; Motor Function; General Academic Achievement; and Mathematics Achievement. RESULTS Meta-analyses showed that, by age 16, individuals who subsequently developed schizophrenia/SSD displayed significant deficits in IQ (d=0.51) and motor function (d=0.56), but not in general academic achievement (d=0.25) or mathematics achievement (d=0.21). Subsidiary analysis indicated that the IQ deficit was present by age 13. CONCLUSIONS These results demonstrate that deficits in IQ and motor performance precede the prodrome and the onset of illness.


Schizophrenia Research | 2010

Neurocognitive performance in children aged 9-12 years who present putative antecedents of schizophrenia

Alexis E. Cullen; Hannah Dickson; Sophie West; Robin G. Morris; Glenn L. Mould; Sheilagh Hodgins; Robin M. Murray; Kristin R. Laurens

BACKGROUND We previously developed a novel method of identifying children aged 9-12 years who may be at elevated risk of developing schizophrenia and the spectrum disorders because they present a triad of putative antecedents of schizophrenia (ASz). The present study aimed to determine whether ASz children also present neurocognitive deficits that are commonly observed in patients with schizophrenia. METHODS Twenty-eight ASz children and 28 typically-developing (TD) children without the antecedents of schizophrenia completed a battery of neurocognitive tests assessing seven domains of function: General intelligence, scholastic achievement, verbal memory, visual memory, working memory, executive function (EF)-verbal fluency, and EF-inhibition. RESULTS Relative to TD children, the ASz group showed poorer performance on all neurocognitive tests (mean Cohens d effect size=0.52). In linear regression analyses, group status (ASz vs. TD) significantly predicted scores on the general intelligence, verbal memory, working memory, and EF-inhibition domains (p<0.05). The severity of problems on each of the individual antecedents comprising the antecedent triad did not relate strongly to performance on the neurocognitive domains. CONCLUSIONS Children aged 9-12 years who present multiple antecedents of schizophrenia display poorer neurocognition than healthy peers on several domains showing pronounced deficits in schizophrenia, first-episode psychosis, and youth with prodromal symptoms. Longitudinal follow-up is necessary to determine the extent to which poorer neurocognitive performance is specific to those who develop schizophrenia.


Epidemiologic Reviews | 2015

Aggressive and Violent Behavior Among Military Personnel Deployed to Iraq and Afghanistan: Prevalence and Link With Deployment and Combat Exposure

Deirdre MacManus; Roberto J. Rona; Hannah Dickson; Greta Somaini; Nicola T. Fear; Simon Wessely

A systematic review and meta-analyses were conducted on studies of the prevalence of aggressive and violent behavior, as well as of violent offenses and convictions, among military personnel following deployment to Iraq and/or Afghanistan; the relationship with deployment and combat exposure; and the role that mental health problems, such as post-traumatic stress disorder (PTSD), have on the pathway between deployment and combat to violence. Seventeen studies published between January 1, 2001, and February 12, 2014, in the United States and the United Kingdom met the inclusion criteria. Despite methodological differences across studies, aggressive behavior was found to be prevalent among serving and formerly serving personnel, with pooled estimates of 10% (95% confidence interval (CI): 1, 20) for physical assault and 29% (95% CI: 25, 36) for all types of physical aggression in the last month, and worthy of further exploration. In both countries, rates were increased among combat-exposed, formerly serving personnel. The majority of studies suggested a small-to-moderate association between combat exposure and postdeployment physical aggression and violence, with a pooled estimate of the weighted odds ratio = 3.24 (95% CI: 2.75, 3.82), with several studies finding that violence increased with intensity and frequency of exposure to combat traumas. The reviews findings support the mediating role of PTSD between combat and postdeployment violence and the importance of alcohol, especially if comorbid with PTSD.


Psychological Medicine | 2008

The inability to ignore: distractibility in women with restricting anorexia nervosa

Hannah Dickson; Samantha J. Brooks; Rudolf Uher; K. Tchanturia; Janet Treasure; Iain C. Campbell

BACKGROUND Attentional difficulties reported in individuals with anorexia nervosa (AN) may be due to preferential processing of disease-salient stimuli at a pre-attentive or at a conscious level or to a general problem in attention. Attentional difficulties may be associated with duration of illness. METHOD Female participants with AN (restricting subtype; n=24) and healthy comparison women (n=24) were randomly allocated to subliminal or supraliminal exposure to visual stimuli (food, neutral and aversive images) while performing the 1-back and 2-back working-memory tasks. RESULTS Participants with AN made fewer errors than the healthy comparison group in the subliminal condition but significantly more errors in the supraliminal condition [condition x group interaction, F(1, 44)=6.82, p<0.01]: this was irrespective of stimulus type (food, neutral and aversive) and task (1-back or 2-back). The total number of errors made correlated positively with the duration of the AN for both the 1-back task (rs=0.46, p<0.05) and for the 2-back task (rs=0.53, p<0.01). CONCLUSIONS Decreased ability to concentrate in the presence of explicit distracters is a feature of AN and is associated with longer duration of illness. This phenomenon could be addressed in psychological interventions.


Journal of Psychiatric Research | 2014

Cognitive impairment among children at-risk for schizophrenia.

Hannah Dickson; Alexis E. Cullen; Abraham Reichenberg; Sheilagh Hodgins; Desmond D. Campbell; Robin G. Morris; Kristin R. Laurens

Adults with schizophrenia present cognitive impairments, as do individuals at ultra-high risk for the disorder, youth with relatives with schizophrenia spectrum disorders, and children with antecedents of schizophrenia. The present study aimed to determine if impairments in childhood differed depending on the definition of risk and/or on the degree of relatedness to an affected individual, and if impairments were explained by IQ. Four groups of children aged 9-12 years were studied: (1) 13 children with ≥1 first-degree or ≥2 second-degree affected relatives (high familial loading: FHx(H)); (2) 14 with ≥1 affected second-degree relative (lower familial loading: FHx(L)); (3) 32 with well-replicated antecedents of schizophrenia (ASz); and (4) 45 typically-developing (TD) children with neither a positive family history nor antecedents. Compared to TD children, both FHx(H) and ASz children exhibited significantly poorer verbal comprehension, scholastic achievement, and verbal working memory, while FHx(H) children additionally displayed significantly lower full-scale IQ, and verbal memory and executive function impairments. After adjusting statistical analyses for IQ, group differences were attenuated. Relative to TD children, FHx(L) children showed no significant differences in performance. The results imply that impairments in verbal comprehension, scholastic achievement, and verbal working memory may index vulnerability for schizophrenia among children with affected relatives with the disorder and among those with multiple antecedents of the disorder who have no affected relatives. More accurate identification of children at-risk for schizophrenia and the specific deficits that they present provides opportunities for interventions such as cognitive remediation that may impact the development of the illness.


Schizophrenia Bulletin | 2014

Misperceptions of Facial Emotions Among Youth Aged 9–14 Years Who Present Multiple Antecedents of Schizophrenia

Hannah Dickson; Monica E. Calkins; Christian G. Kohler; Sheilagh Hodgins; Kristin R. Laurens

Similar to adults with schizophrenia, youth at high risk for developing schizophrenia present difficulties in recognizing emotions in faces. These difficulties might index vulnerability for schizophrenia and play a role in the development of the illness. Facial emotion recognition (FER) impairments have been implicated in declining social functioning during the prodromal phase of illness and are thus a potential target for early intervention efforts. This study examined 9- to 14-year-old children: 34 children who presented a triad of well-replicated antecedents of schizophrenia (ASz), including motor and/or speech delays, clinically relevant internalizing and/or externalizing problems, and psychotic-like experiences (PLEs), and 34 typically developing (TD) children who presented none of these antecedents. An established FER task (ER40) was used to assess correct recognition of happy, sad, angry, fearful, and neutral expressions, and facial emotion misperception responses were made for each emotion type. Relative to TD children, ASz children presented an overall impairment in FER. Further, ASz children misattributed neutral expressions to face displaying other emotions and also more often mislabeled a neutral expression as sad compared with healthy peers. The inability to accurately discriminate subtle differences in facial emotion and the misinterpretation of neutral expressions as sad may contribute to the initiation and/or persistence of PLEs. Interventions that are effective in teaching adults to recognize emotions in faces could potentially benefit children presenting with antecedents of schizophrenia.


Schizophrenia Bulletin | 2018

T74. ACADEMIC ACHIEVEMENT AND SCHIZOPHRENIA: A META-ANALYSIS

Hannah Dickson; Alexis E. Cullen; Sheilagh Hodgins; James H. MacCabe; Kristin R. Laurens

Abstract Background The extent to which poor academic achievement is associated with later schizophrenia is unclear. The aim of the present study was to update our prior meta-analyses which examined academic achievement in youth aged 16 years or younger who later developed schizophrenia or schizophrenia spectrum disorders (SSD) and those who did not (Dickson et al, 2012, Psychological Medicine, 42, 743–755). We also conducted a new meta-analysis on published studies that reported on general academic achievement in youth at-risk for schizophrenia/SSD aged 16 years or younger compared to typically developing youth Methods In addition to the five studies included in our earlier meta-analyses, a further three prospective investigations of birth or genetic high-risk cohorts were identified that reported results using objective measures of general academic achievement and of mathematics achievement for individuals who did and did not develop schizophrenia/SSD in adulthood. For our new meta-analysis we identified a total of seven studies that met the following inclusion criteria: (1) written in English; (2) objective measure of general academic achievement consisting of scores on least two core academic subjects (i.e., literacy and mathematics) at age 16 years or younger; (3) results provided for youth at high risk for developing schizophrenia/SSD in adulthood by virtue of having at least one first-degree relative with the disorder or reporting psychotic like-experiences (PLEs); and (4) sufficient data to calculate effect sizes. Results Meta-analyses showed that by age 16 years, individuals who later developed schizophrenia/SSD presented with significantly poorer general academic achievement (d=-0.26) and mathematics achievement (d=-0.21). Findings also indicated that during adolescence, youth with a family history of schizophrenia/SSD and youth reporting PLES were characterised by significantly lower general academic achievement than healthy peers (d=-0.39; d=-0.53, respectively). Discussion These results show that poor academic achievement precedes illness onset, and may represent an easily identifiable non-specific marker of biological, psychological and social risk processes underpinning the development of schizophrenia/SSD.


Brain Behavior and Immunity | 2017

The relationship between salivary C-reactive protein and cognitive function in children aged 11–14 years: Does psychopathology have a moderating effect?

Alexis E. Cullen; Ben M. Tappin; Patricia A. Zunszain; Hannah Dickson; Ruth E. Roberts; Naghmeh Nikkheslat; Mizan Khondoker; Carmine M. Pariante; Helen L. Fisher; Kristin R. Laurens

Highlights • Salivary CRP predicts poorer executive functioning in children aged 11–14 years.• The association is not confounded or moderated by concurrent psychopathology.• Findings have implications for interventions targeting cognitive deficits.• Salivary CRP can be used to investigate inflammation-brain function relationships.


Trauma, Violence, & Abuse | 2018

Prevalence of Self-Reported Intimate Partner Violence Victimization Among Military Personnel: A Systematic Review and Meta-Analysis:

Katherine Sparrow; Hannah Dickson; Jamie Kwan; Louise M. Howard; Nicola T. Fear; Deirdre MacManus

Background: Research on intimate partner violence (IPV) in the military has tended to focus on military personnel as perpetrators and civilian partners/spouses as victims. However, studies have found high levels of IPV victimization among military personnel. This article systematically reviews studies of the prevalence of self-reported IPV victimization among military populations. Methods: Searches of four electronic databases (Embase, Medline, PsycINFO, and Web of Science) were supplemented by reference list screening. Meta-analyses of the available data were performed, where possible, using the random effects model. Results: This review included 28 studies with a combined sample of 69,808 military participants. Overall, similar or higher prevalence rates of physical IPV victimization were found among males compared to females and this was supported by a meta-analytic subgroup analysis: pooled prevalence of 21% (95% confidence interval [CI] = [17.4, 24.6]) among males and 13.6% among females (95% CI [9.5, 17.7]). Psychological IPV was the most prevalent type of abuse, in keeping with findings from the general population. There were no studies on sexual IPV victimization among male personnel. Evidence for the impact of military factors, such as deployment or rank, on IPV victimization was conflicting. Discussion: Prevalence rates varied widely, influenced by methodological variation among studies. The review highlighted the lack of research into male IPV victimization in the military and the relative absence of research into impact of IPV. It is recommended that future research disaggregates results by gender and considers the impact of IPV, in order that gender differences can be uncovered.


Schizophrenia Research | 2014

Poster #S150 HYPOTHALAMIC-PITUITARY-ADRENAL AXIS DYSFUNCTION: AN EARLY MARKER OF PSYCHOSIS VULNERABILITY?

Alexis E. Cullen; Hannah Dickson; Ruth E. Roberts; Patricia A. Zunszain; Carmine M. Pariante; Kristin R. Laurens

Abnormal hypothalamic-pituitary-adrenal (HPA) axis function, as indexed by elevated diurnal cortisol levels and a blunted cortisol awakening response (CAR), has been observed among patients with first- episode psychosis and also has been associated with neurocognitive deficits in this population . However, the extent to which HPA axis dysfunction precedes illness onset is currently unclear . Whilst elevated diurnal cortisol levels have been reported in samples of youth at ultra high-risk for psychosis, such elevations may relate to distress associated with emerging illness and might also be influenced by psychotropic medication . Further- more, studies of high-risk individuals with a family history of illness have typically included adult relatives who have passed the peak age of illness onset . As yet, no study of high-risk youth has examined the CAR or the extent to which HPA axis dysfunction is associated with neurocognitive performance . The current study aimed to determine whether children at putatively elevated risk for schizophrenia who present psychotic-like experiences and other antecedents of schizophrenia (ASz) and high-risk children with a family history of illness (FHx) are characterised by abnormal HPA axis function relative to their typically-developing (TD) peers . A further aim was to examine associations between HPA axis function and performance on tasks of memory and executive function among ASz and FHx children .

Collaboration


Dive into the Hannah Dickson's collaboration.

Top Co-Authors

Avatar

Kristin R. Laurens

University of New South Wales

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge