An exploration of varieties of visual attention: ERP findings

A set of five tasks was designed to examine dynamic aspects of visual attention: selective attention to color, selective attention to pattern, dividing and switching attention between color and pattern, and selective attention to pattern with changing target. These varieties of visual attention were examined using the same set of stimuli under different instruction sets; thus differences between tasks cannot be attributed to differences in the perceptual features of the stimuli. ERP data are presented for each of these tasks. A within-task analysis of different stimulus types varying in similarity to the attended target feature revealed that an early frontal selection positivity (FSP) was evident in selective attention tasks, regardless of whether color was the attended feature. The scalp distribution of a later posterior selection negativity (SN) was affected by whether the attended feature was color or pattern. The SN was largely unaffected by dividing attention across color and pattern. A large widespread positivity was evident in most conditions, consisting of at least three subcomponents which were differentially affected by the attention conditions. These findings are discussed in relation to prior research and the time course of visual attention processes in the brain. (C) 1999 Elsevier Science B.V. All rights reserved.

Self-awareness and psychosocial functioning following acquired brain injury: An evaluation of a group support programme

This study investigated a group support programme designed to improve self-awareness deficits and psychosocial functioning in a group of chronic patients (N = 21) with acquired brain injury (ABI). The participants were on average 8.6 years (range: 1-36 years) post-injury and were seen at the Brain Injury Association of Queensland, Australia. The assessment of participants involved two standardised measures of intellectual self-awareness with collateral reports from relatives. The present study introduced a new measure called the Self-Regulation Skills Interview (SRSI) which assessed higher levels of self awareness and self-regulation skills. Psychosocial functioning was assessed using a standardised self-report measure. At baseline the group had a relatively high level of intellectual self-awareness regarding their deficits, a low to moderate level of self-regulation skills, and significant psychosocial impairment. The participants were involved in a 16-week group programme which involved components of cognitive rehabilitation, cognitive-behavioural therapy, and social skills training. A post-intervention assessment indicated that participants had significantly improved levels of self-regulation skills and psychosocial functioning. A 6-month follow-up assessment indicated that overall, participants had maintained the gains made during the programme. The important role of self-regulation skills is emphasised as the principle factor contributing to the maintenance of the gains observed.

Attention Deficit Hyperactivity Disorder and substance use disorders: is there a causal link?

Attention-deficit hyperactivity disorder (ADHD), characterized by restless, inattentive and hyperactive behaviours, is a relatively common childhood disorder that affects approximately 5% of the general population. There has been controversy about whether ADHD increases risks of developing substance use disorders. The available evidence suggests that, in the absence of conduct disorder, ADHD is not associated with an increased risk of substance use problems in males. There is only limited evidence on the role of ADHD in the aetiology of substance use disorders among females. While ADHD has traditionally been considered as a childhood disorder, it may also occur in adults; research needs to examine the extent to which ADHD in adulthood increases the risk of substance use disorders.

Local-global processing in early-onset schizophrenia: Evidence for an impairment in shifting the spatial scale of attention

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. (C) 2003 Elsevier Science (USA). All rights reserved.

A qualitative study of Australian GPs' attitudes and practices in the diagnosis and management of attention-deficit/hyperactivity disorder (ADHD)

Background. The importance of general practice involvement in the care of attention-deficit/hyperactivity disorder (ADHD) is increasing due to the rising numbers of patients who present with the disorder. It has been suggested by consensus bodies that GPs should be identifying and referring patients at the severe end of the ADHD spectrum and managing those with less severe symptoms. However, GPs' views of their role in ADHD care are unknown. Objective. Our aim was to explore the attitudes and practices of Australian GPs towards the diagnosis and management of ADHD. Methods. We conducted a series of focus groups to explore GPs' beliefs regarding the causes of ADHD, their perceived role in ADHD diagnosis and management and their views on the role of behaviour therapies and pharmacotherapies in ADHD management. The subjects were 28 GPs in six focus groups. Results. GPs in this study did not want to be the primary providers of care for patients with ADHD. Participants indicated a preference to refer the patient to medical specialists for diagnosis and treatment of ADHD, and expressed low levels of interest in becoming highly involved in ADHD care. Concerns about overdiagnosis and misdiagnosis of the disorder, diagnostic complexity, time constraints, insufficient education and training about the disorder, and concerns regarding misuse and diversion of stimulant medications were the reasons cited for their lack of willingness. Conclusions. The Australian GPs in this study identify a role for themselves in ADHD care which is largely supportive in nature, and involves close liaison with specialist services.

Can I have your attention please: Repressors and enhanced P3 to emotional stimuli

In four experiments ERPs to emotional (negative and positive) and neutral stimuli were examined as a function of participants’ trait anxiety and repressivedefensiveness. The experiments investigated the time course of attentional bias in the processing of such stimuli. Pictures of angry, happy, and neutral faces were used in two of the experiments and pictures ofmutilated, happy, and neutral faces were used in the others. ERP’s to emotional and neutral stimuli were recorded from parietal, temporal, and frontal sites. Analysis of the P3 component indicated that the peak magnitude of the P3 at the parietal and temporal sites reflected an interactive function of trait anxiety and defensiveness. Repressors (low reported anxiety, high defensiveness) showed a consistent pattern of greater P3 magnitude at the parietal and temporal sites for emotional faces (angry, happy, and mutilated) than did high-anxious and low-anxious participants. Participants did not differ in P3 magnitude when ERPs to neutral stimuli were investigated (e.g., a fixation cross). The findings indicate that Repressors dedicate greater processing resources to emotional material, as compared to neutral material, than either the high-anxious or low-anxious individuals. Results of the four experiments are discussed within the theoretical framework of Derakshan and Eysenck (1998). The importance of understanding the role of differences in information processing, in the experience and avoidance of emotional information, as a function of trait anxiety and defensiveness is emphasized.

Cost-effectiveness of dexamphetamine and methylphenidate for the treatment of childhood attention deficit hyperactivity disorder

Objective: To analyze from a health sector perspective the cost-effectiveness of dexamphetamine (DEX) and methylphenidate (MPH) interventions to treat childhood attention deficit hyperactivity disorder (ADHD), compared to current practice. Method: Children eligible for the interventions are those aged between 4 and 17 years in 2000, who had ADHD and were seeking care for emotional or behavioural problems, but were not receiving stimulant medication. To determine health benefit, a meta-analysis of randomized controlled trials was performed for DEX and MPH, and the effect sizes were translated into utility values. An assessment on second stage filter criteria ('equity', 'strength of evidence', 'feasibility' and 'acceptability to stakeholders') is also undertaken to incorporate additional factors that impact on resource allocation decisions. Simulation modelling techniques are used to present a 95% uncertainty interval (UI) around the incremental cost-effectiveness ratio (ICER), which is calculated in cost (in A$) per DALY averted. Results: The ICER for DEX is A$4100/DALY saved (95% UI: negative to A$14 000) and for MPH is A$15 000/DALY saved (95% UI: A$9100-22 000). DEX is more costly than MPH for the government, but much less costly for the patient. Conclusions: MPH and DEX are cost-effective interventions for childhood ADHD. DEX is more cost-effective than MPH, although if MPH were listed at a lower price on the Pharmaceutical Benefits Scheme it would become more cost-effective. Increased uptake of stimulants for ADHD would require policy change. However, the medication of children and wider availability of stimulants may concern parents and the community.

Fronto-parietal activation in attention-deficit hyperactivity disorder, combined type: functional magnetic resonance imaging study

A functional magnetic resonance imaging mental rotation paradigm was used to investigate the patterns of activation of fronto-parietal brain areas in male adolescents with attention-deficit hyperactivity disorder, combined type (ADHD-CT) compared with age-, gender-, handedness- and performance IQ-matched healthy controls. The ADHD-CT group had (a) decreased activation of the 'action-attentional' system (including Brodmann's areas (BA) 46, 39,40) and the superior parietal (BA7) and middle frontal (BA10) areas and (b) increased activation of the posterior midline attentional system. These different neuroactivation patterns indicate widespread frontal, striatal and parietal dysfunction in adolescents with ADHD-CT. Declaration of interest None.

Association between dopamine transporter (DATI) genotype, left-sided inattention, and an enhanced response to methylphenidate in attention-deficit hyperactivity disorder

A polymorphism of the dopamine transporter gene (DAT1, 10-repeat) is associated with attention-deficit hyperactivity disorder (ADHD) and has been linked to an enhanced response to methylphenidate (MPH). One aspect of the attention deficit in ADHD includes a subtle inattention to left space, resembling that seen after right cerebral hemisphere damage. Since left-sided inattention in ADHD may resolve when treated with MPH, we asked whether left-sided inattention in ADHD was related to DAT1 genotype and the therapeutic efficacy of MPH. A total of 43 ADHD children and their parents were genotyped for the DAT1 30 variable number of tandem repeats polymorphism. The children performed the Landmark Test, a well-validated measure yielding a spatial attentional asymmetry index ( leftward to rightward attentional bias). Parents rated their child's response to MPH retrospectively using a three-point scale ( no, mediocre or very good response). Additionally, parents used a symptom checklist to rate behavior while on and off medication. A within-family control design determined whether asymmetry indices predicted biased transmission of 10-repeat parental DAT1 alleles and/or response to MPH. It was found that left-sided inattention predicted transmission of the 10-repeat allele from parents to probands and was associated with the severity of ADHD symptomatology. Children rated as achieving a very good response to MPH displayed left-sided inattention, while those rated as achieving a poorer response did not. Our results suggest a subgroup of children with ADHD for whom the 10-repeat DAT1 allele is associated with left-sided inattention. MPH may be most efficacious in this group because it ameliorates a DAT1-mediated hypodopaminergic state.

Depression in women living with HIV: clinical and psychosocial correlates

The number of Brazilian women living with HIV has increased significantly in past years, rendering studies of their particular care demands including psychiatric issues. This study measures the prevalence of major depression, using the Structured Clinical Interview for DSM-IV Axis I Disorders, in a sample of 120 women living with HIV in treatment at a reference centre in So Paulo. Socio-demographic variables, HIV-related clinical and laboratory data, including CD4+ cell counts and HIV plasma viral loads, as well as psychosocial features (intimate relationships, disclosure of HIV serostatus, partner`s serostatus and patient`s emotional and financial support) were investigated as factors potentially associated with depression. The prevalence of major depression at the time of evaluation was 25.8% (95% CI 18.2-33.4%). Clinical status (p = 0.002), lack of emotional support (p = 0.02), use of antidepressants (p = 0.028) and length of time since HIV diagnosis (p = 0.05) were associated with major depression in univariate analysis. In multivariate multiple-regression model, HIV clinical status, lack of emotional support and higher plasma viral loads were associated with depression. Sixty per cent of the women have a major depression diagnosis during lifetime. We conclude that major depression is highly prevalent among women living with HIV, but it is still underdiagnosed and undertreated.

Psychosocial pathways to inconsistent condom use among male sex workers: personality, drug misuse and criminality

Background: This research compared street male sex workers in Santo Andre, Brazil, that reported consistent condom use with those that revealed inconsistent condom use with their clients, concerning personality aspects, impulsiveness, alcohol and drug consumption, depressive symptoms, sociodemographic data and criminal involvement. Methods: Eighty-six male sex workers were evaluated in face-to-face interviews at their place of work. A `snowball` sampling procedure was used to access this hard-to-reach population. Findings: Male sex workers with inconsistent condom use showed greater involvement with criminal activities, higher reward dependence level and more frequent self-report of being HIV-positive. Conclusions: Conceptualisation of male sex workers` psychological characteristics may be required where HIV risk is not only attributed to sex work per se, but to other aspects such as personality-related factors and negative identity.

Psychosocial sequelae of the 1989 Newcastle earthquake .2. Exposure and morbidity profiles during the first 2 years post-disaster

Background. A sample of 1089 Australian adults was selected for the longitudinal component of the Quake Impact Study, a 2-year, four-phase investigation of the psychosocial effects of the 1989 Newcastle earthquake. Of these, 845 (78%) completed a survey 6 months post-disaster as well as one or more of the three follow-up surveys. Methods. The phase I survey was used to construct dimensional indices of self-reported exposure to threat the disruption and also to classify subjects by their membership of five 'at risk' groups (the injured; the displaced; owners of damaged small businesses; helpers in threat and non-threat situations). Psychological morbidity was assessed at each phase using the 12-item General Health Questionnaire (GHQ-12) and the Impact of Event Scale (IES). Results. Psychological morbidity declined over time but tended to stabilize at about 12 months post-disaster for general morbidity (GHQ-12) and at about 18 months for trauma-related (IES) morbidity. Initial exposure to threat and/or disruption were significant predictors of psychological morbidity throughout the study and had superior predictive power to membership of the targeted 'at risk' groups. The degree of ongoing disruption and other life events since the earthquake were also significant predictors of morbidity. The injured reported the highest levels of distress, but there was a relative absence of morbidity among the helpers. Conclusions. Future disaster research should carefully assess the threat and disruption experiences of the survivors at the time of the event and monitor ongoing disruptions in the aftermath in order to target interventions more effectively.

Psychosocial sequelae of the 1989 Newcastle earthquake .3. Role of vulnerability factors in postdisaster morbidity

Background. This paper examines the contributions of dispositional and non-dispositional factors to post-disaster psychological morbidity. Data reported are from the 845 participants in the longitudinal component of the Quake Impact Study. Methods. The phase 1 survey was used to construct dimensional indices of threat and disruption exposure. Subsequently, a range of dispositional characteristics were measured, including neuroticism, personal hopefulness and defence style. The main morbidity measures were the General Health Questionnaire (GHQ-12) and Impact of Event Scale (IES). Results. Dispositional characteristics were the best predictors of psychological morbidity throughout the 2 years post-disaster, contributing substantially more to the variance in morbidity (12-39%) than did initial exposure (5-12%), but the extent of their contribution was greater for general (GHQ-12) than for post-traumatic (IES) morbidity. Among the non-dispositional factors, avoidance coping contributed equally to general and post-traumatic morbidity (pr = 0.24). Life events since the earthquake (pr = 0.18), poor social relationships (pr = -0.25) and ongoing earthquake-related disruptions (pr = 0.22) also contributed to general morbidity, while only the latter contributed significantly to post-traumatic morbidity (pr = 0.15). Conclusions. Medium-term post-earthquake morbidity appears to be a function of multiple factors whose contributions vary depending on the type of morbidity experienced and include trait vulnerability, the nature and degree of initial exposure, avoidance coping and the nature and severity of subsequent events.