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Potential Endophenotypes (potential + endophenotype)
Selected AbstractsSustained attention as a potential endophenotype for bipolar disorderACTA PSYCHIATRICA SCANDINAVICA, Issue 3 2010I. Ancín Ancín I, Santos JL, Teijeira C, Sánchez-Morla EM, Bescós MJ, Argudo I, Torrijos S, Vázquez-Álvarez B, De La Vega I, López-Ibor JJ, Barabash A, Cabranes-Díaz JA. Sustained attention as a potential endophenotype for bipolar disorder. Objective:, Nowadays, it is accepted that to identify the biological basis of psychiatric illnesses it would be useful to deconstruct them into the most basic manifestations, such as cognitive deficits. The aim of this study was to set attention deficit as a stable vulnerability marker of bipolar disorder. Method:, Sustained attention was evaluated by the Continuous Performance Test (DS-CPT) in 143 euthymic bipolar patients and 105 controls. To estimate the influence of clinical profile in attention, patients completed a semi-structured interview. Results:, Bipolar patients showed a deficit in attention during euthymic periods. This disturbance correlated with years of evolution, age of onset and age of first hospitalisation; and was not influenced by other clinical data. Conclusion:, Sustained attention may be considered as an endophenotype of the illness. [source] Critical evaluation of cognitive dysfunctions as endophenotypes of schizophreniaACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2004S. Kéri Objective:, Cognitive dysfunctions are potential endophenotypes of schizophrenia. The aim of this study was to investigate whether recent evidence indeed suggests that cognitive dysfunctions are potent indicators of specific genetic traits that represent susceptibility for schizophrenia. Method:, Studies including large, well-defined samples and controlled cognitive assessment have been reviewed. Results:, Evidence suggests that schizophrenia patients and their unaffected biological relatives are impaired in several cognitive domains, including working memory, executive functions, sustained attention, verbal episodic memory, processing of visual and auditory stimuli, and smooth pursuit eye movements. However, these impairments are present only in a limited proportion of subjects, showing low specificity and sensitivity and high variability. Linkage with specific genes is weak. Conclusion:, Although some results are promising, at present cognitive dysfunctions cannot be considered as highly sensitive and specific endophenotypes of schizophrenia. [source] Profiles of executive function in parents and siblings of individuals with autism spectrum disordersGENES, BRAIN AND BEHAVIOR, Issue 8 2006D. Wong Delineation of a cognitive endophenotype for autism is useful both for exploring the genetic mechanisms underlying the disorder and for identifying which cognitive traits may be primary to it. This study investigated whether first-degree relatives of individuals with autism spectrum disorders (ASDs) demonstrate a specific profile of performance on a range of components of executive function (EF), to determine whether EF deficits represent possible endophenotypes for autism. Parents and siblings of ASD and control probands were tested on EF tasks measuring planning, set-shifting, inhibition and generativity. ASD parents showed poorer performance than control parents on a test of ideational fluency or generativity, and ASD fathers demonstrated a weakness in set-shifting to a previously irrelevant dimension. ASD siblings revealed a mild reduction in ideational fluency and a weakness in non-verbal generativity when compared with control siblings. Neither ASD parents nor siblings displayed significant difficulties with planning or inhibition. These results indicated that the broad autism phenotype may not be characterized primarily by impairments in planning and cognitive flexibility, as had been previously proposed. Weaknesses in generativity emerged as stronger potential endophenotypes in this study, suggesting that this aspect of EF should play a central role in cognitive theories of autism. However, discrepancies in the EF profile demonstrated by parents and siblings suggest that factors related to age or parental responsibility may affect the precise pattern of deficits observed. [source] Auditory P300 Event-Related Potentials and Neurocognitive Functions in Opioid Dependent Men and Their BrothersTHE AMERICAN JOURNAL ON ADDICTIONS, Issue 3 2009Shubh Mohan Singh MD Event-related-potentials (especially P300) and cognitive functioning as potential endophenotypes have not been studied in opioid dependence. We compared auditory P300 and cognitive functions in opioid-dependent men, their brothers and normal controls in an exploratory study with a view to find shared genetic factors in the development of opioid dependence. Twenty abstinent opioid-dependent males, their brothers and twenty matched controls were administered Wisconsin card sorting test (WCST), digit span test, trail making test-B, and auditory event-related potentials (P300) from an oddball task were recorded. The opioid dependent group performed the worst, the brothers group was intermediate, and the control group performed the best on tests of WCST, digit span and trail making test-B. The opioid dependent group had the smallest amplitudes and longest latencies of P300, and was followed by the brothers group who had an intermediate position and the control group who had the largest amplitudes and the shortest latencies. P300 and executive neurocognitive functions can be considered endophenotypes for the genetic study of vulnerability to opioid dependence. These are reflective of executive dysfunction and disrupted behavioral inhibition and the intermediate position of brothers suggests a common genetic substrate as a component of the etiology. [source] Executive functions as endophenotypes in ADHD: evidence from the Cambridge Neuropsychological Test Battery (CANTAB)THE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 7 2010Susan Shur-Fen Gau Background:, Little is known about executive functions among unaffected siblings of children with attention deficit/hyperactivity disorder (ADHD), and there is lack of such information from non-Western countries. We examined verbal and nonverbal executive functions in adolescents with ADHD, unaffected siblings and controls to test whether executive functions could be potential endophenotypes for ADHD. Methods:, We assessed 279 adolescents (age range: 11,17 years) with a childhood diagnosis of DSM-IV ADHD, 136 biological siblings (108 unaffected, 79.4%), and 173 unaffected controls by using psychiatric interviews, the Wechsler Intelligence Scale for Children , 3rd edition (WISC-III), including digit spans, and the tasks involving executive functions of the Cambridge Neuropsychological Test Automated Battery (CANTAB): Intra-dimensional/Extra-dimensional Shifts (IED), Spatial Span (SSP), Spatial Working Memory (SWM), and Stockings of Cambridge (SOC). Results:, Compared with the controls, adolescents with ADHD and unaffected siblings had a significantly shorter backward digit span, more extra-dimensional shift errors in the IED, shorter spatial span length in the SSP, more total errors and poorer strategy use in the SWM, and fewer problems solved in the minimum number of moves and shorter initial thinking time in the SOC. The magnitudes of the differences in the SWM and SOC increased with increased task difficulties. In general, neither persistent ADHD nor comorbidity was associated with increased deficits in executive functions among adolescents with ADHD. Conclusions:, The lack of much difference in executive dysfunctions between unaffected siblings and ADHD adolescents suggests that executive dysfunctions may be useful cognitive endophenotypes for ADHD genetic studies. [source] Abnormal dose-response melatonin suppression by light in bipolar type I patients compared with healthy adult subjectsACTA NEUROPSYCHIATRICA, Issue 5 2009Karen T. Hallam Objective: Among potential endophenotypes proposed for bipolar affective disorder focusing on circadian abnormalities associated with the illness has particularly high face validity. Melatonin sensitivity to light is one circadian endophenotype proposed as useful in bipolar disorder. The aim of this study was to investigate melatonin sensitivity to light over a range of light intensities in order to compare and contrast responses in bipolar I patients with those of healthy adult volunteers. Methods: The study included seven patients (4 females, 3 males) with bipolar I disorder and 34 control participants (22 females, 12 males) with no personal or family history of affective illness. Melatonin sensitivity to light was determined in all patients and participants across a range of light intensities (0, 200, 500 and 1000 lux). Results: The results indicated that patients showed melatonin super-sensitivity to light in comparison with controls, a response that was consistent across the entire light intensity range investigated. Conclusion: The study provides further evidence for a super sensitive response in bipolar I patients and suggests that its potential usefulness as an endophenotypic marker of the illness is deserving of further research. [source] | ||||||||||