A single nucleotide polymorphism rs12807809 located upstream of the neurogranin (NRGN) gene has been identified as a risk variant for schizophrenia in recent genome-wide association studies. To date, there has been little investigation of the endophenotypic consequences of this variant, and our own investigations have suggested that the effects of this gene are not apparent at the level of cognitive function in patients or controls. Because the impact of risk variants may be more apparent at the level of brain, the aim of this investigation was to delineate whether NRGN genotype predicted variability in brain structure and/or function. Healthy individuals participated in structural (N = 140) and/or functional (N = 36) magnetic resonance imaging (s/fMRI). Voxel-based morphometry was used to compare gray and white matter volumes between carriers of the non-risk C allele (i.e., CC/CT) and those who were homozygous for the risk T allele. Functional imaging data were acquired during the performance of a spatial working memory task, and were also analyzed with respect to the difference between C carriers and T homozygotes. There was no effect of the NRGN variant rs12807809 on behavioral performance or brain structure. However, there was a main effect of genotype on brain activity during performance of the working memory task, such that while C carriers exhibited a load-independent decrease in left superior frontal gyrus/BA10, TT individuals failed to show a similar decrease in activity. The failure to disengage this ventromedial prefrontal region, despite preserved performance, may be indicative of a reduction in processing efficiency in healthy TT carriers. Although it remains to be established whether this holds true in larger samples and in patient cohorts, if valid, this suggests a potential mechanism by which NRGN variability might contribute to schizophrenia risk.

This study aimed to investigate the effects of methylphenidate on children with Attention Deficit Hyperactivity Disorder (ADHD). The study employed a conceptual framework of attention, consistent with contemporary theory, and including the following components: sustained attention, selective attention, divided attention, shifting attention, and speed of information processing. Fifteen children (12 boys and 3 girls) of normal intelligence, with a diagnosis of ADHD according to the DSM-IV criteria, and ranging in age from 8 to 11 years participated in the study. Children's attentional abilities were evaluated using the Test of Everyday Attention for Children (TEA-Ch: Manly, Roberston, Anderson, & Nimmo-Smith, 1999). A double-blind counterbalanced repeated-measures design approach was employed to tap on–off medication effects, and deviations from normal. Results showed that comparisons between on–off medication conditions generally detected few differences with respect to sustained and selective attention measures and simple processing speed. In contrast, for higher-level attention domains, including shifting and divided attention, children on medication demonstrated a speed–accuracy trade-off, exhibiting greater accuracy, but slower completion times. When data from the ADHD group were compared to controls a consistent pattern emerged, with children with ADHD in the medication condition being more accurate across all attention domains on all measures. While these children also tended to record slower completion times, group differences and effect sizes were of smaller magnitude. The findings of this study suggest a possible speed–accuracy trade-off effect for children with ADHD on medication.

Impaired cognition is a core feature of schizophrenia (SZ) that precedes, accompanies, and often outlasts a patient's clinical symptoms. The success of new generation antipsychotics, as well as their failure to ameliorate the persistent disabilities associated with the disorder are well documented. Consequently, a number of psychosocial and cognitive interventions have been developed to address specific aspects of disability not adequately alleviated by medication.

Among these, interventions adapted from the acquired brain literature that target cognitively based disability (cognitive remediation therapy; CRT) have received significant empirical support both for ameliorating specific deficits in memory, attention and executive function, and improving real world outcome. CRT strategies have focused either on providing drill-based training aimed at increasing capacity or providing behavioural strategies for compensating for cognitive deficits, or a mixture of both. Nonetheless, these interventions have varied widely and several questions remain.

This review provides a brief overview of cognitive remediation therapies in psychosis, discusses evidence for its success, and outlines a number of questions that remain about its implementation. Given the current unavailability of cognitive remediation as part of standard care in Irish mental health services, we conclude by describing one such intervention developed within our clinical research group and the questions we hope to address in making this programme more widely available to Irish patients.

A range of tests of everyday attention is described, based on ecologically plausible activities such as searching maps, looking through telephone directories, and listening to lottery number broadcasts. An age-, sex- and IQ-stratified sample of 154 normal participants was given these tests, along with a number of existing tests of attention. The factor structure revealed by this data set matched well contemporary evidence for a set of functionally independent attentional circuits in the brain, and included factors for sustained attention, selective attention, attentional switching and auditory-verbal working memory. The Test of Everyday Attention (TEA), which was developed and standardized on the basis of these subtests, has three parallel forms, high test-retest reliability, and correlates significantly with existing measures of attention. Furthermore, selected subtests successfully discriminate among a number of brain-impaired groups, including closed head injury versus age-matched controls, minimal versus mild Alzheimer’s disease, and progressive supranuclear palsy patients versus age-matched controls. (JINS, 1996, 2, 525–534.)