The Relation Between Sluggish Cognitive Tempo and DSM-IV ADHD

To test the relation between sluggish cognitive tempo (SCT) and DSM-IV ADHD symptoms, parent and teacher ratings of the 18 DSM-IV ADHD items and five potential SCT items were obtained in a community sample of 8-18 year-old twins that was overselected for ADHD and learning disabilities (n = 296). Confirmatory factor analyses revealed that a three-factor model provided the best fit to the data for both parent and teacher ratings. DSM-IV inattention and hyperactivity-impulsivity symptoms loaded on two factors consistent with the DSM-IV model, and five SCT symptoms loaded primarily on a third factor. The SCT and inattention factors were highly correlated, whereas SCT and hyperactivity-impulsivity were weakly related. Both raters indicated that children meeting symptom criteria for the combined and inattentive subtypes exhibited significantly more SCT symptoms than those meeting symptom criteria for hyperactive-impulsive type and the comparison group without ADHD. Children meeting symptom criteria for the inattentive type exhibited significantly more SCT symptoms than those meeting criteria for the combined type, based on teacher ratings. These results suggest that SCT is an internally consistent construct that is significantly associated with DSM-IV inattention.     

Sex differences in genetic and environmental influences on DSM-III-R attention-deficit/hyperactivity disorder

Approximately 5% of children are affected by attention-deficit/hyperactivity disorder (ADHD), and more boys are affected than girls. This study examined the magnitude of genetic and environmental influences on ADHD and several questions regarding sex differences in its prevalence and liability. The participants were 2,391 twin and sibling pairs from Australia, ages 3-18. ADHD symptoms in the general population were highly heritable (h2 = .85-.90), as were deviant ADHD scores in the selected population. The magnitude of familial influences was similar for boys and girls, although there were shared environmental influences on ADHD in girls but not boys and dominance genetic influences on ADHD in boys but not girls. Specific genetic and environmental influences were highly similar for boys and girls. Evidence supported the polygenic multiple threshold model rather than the constitutional variability model of sex differences in ADHD.     

Mechanisms underlying corruption of working memory in Parkinson's disease

Working memory (WM) impairments are reported to occur in patients with Parkinson's disease (PD). However, the mechanisms are unclear. Here, we investigate several putative factors that might drive poor performance, by examining the precision of recall, the order in which items are recalled and whether memories are corrupted by random guessing (attentional lapses). We used two separate tasks that examined the quality of WM recall under different loads and retention periods, as well as a traditional digit span test. Firstly, on a simple measure of WM recall, where patients were asked to reproduce the orientation of a centrally presented arrow, overall recall was not significantly impaired. However, there was some evidence for increased guessing (attentional lapses). On a new analogue version of the Corsi-span task, where participants had to reproduce on a touchscreen the exact spatial pattern of presented stimuli in the order and locations in which they appeared, there was a reduction in the precision of spatial WM at higher loads. This deficit was due to misremembering item order. At the highest load, there was reduced recall precision, whereas increased guessing was only observed at intermediate set sizes. Finally, PD patients had impaired backward, but not forward, digit spans. Overall, these results reveal the task- and load-dependent nature of WM deficits in PD. On simple low-load tasks, attentional lapses predominate, whereas at higher loads, in the spatial domain, the corruption of mnemonic information—both order item and precision—emerge as the main driver of impairment.     

Genetic and Environmental Contributions to Common Psychopathologies of Childhood and Adolescence: A Study of Twins and Their Siblings

We report findings based on analyses of self-reports of six common adolescent psychopathologies (attention deficit/hyperactivity disorder, ADHD; conduct disorder, CD; oppositional defiant disorder, ODD; generalized anxiety disorder, GAD; separation anxiety disorder, SAD; and major depressive disorder, MDD) in a sample of 1,162 male and female adolescent (12–19 years) twin pairs and 426 siblings. Prevalence statistics for past year and lifetime reports confirm differences between genders for CD, GAD, SAD, and MDD, and a lack of differences between twins and their non-twin siblings. Biometrical modeling was conducted to ascertain the relative influences of genes, and shared and non-shared environments contributing to these disorders. A more robust estimate of these parameters was obtained by including non-twin siblings. Age-specific thresholds were integrated into the analyses to appropriately model the developmental patterns of behavior. We found evidence for both genetic and non-shared environmental influences for all disorders. Shared environmental influences also seem to be important for MDD and lifetime GAD.     

Inductive Reasoning in Alzheimer''s Disease

We evaluated knowledge of basic level and superordinate semantic relations and the role of cognitive resources during inductive reasoning in probable Alzheimer's disease (AD). Nineteen mildly demented AD patients and 17 healthy control subjects judged the truthfulness of arguments with a premise and a conclusion that contain familiar concepts coupled with "blank" predicates, such as "Spiders contain phosphatidylcholine; therefore all insects contain phosphatidylcholine." Like healthy control subjects, AD patients were relatively insensitive to the typicality of the premise category when judging the strength of arguments with a conclusion containing a basic-level concept, but were relatively sensitive to typicality during judgments of arguments containing a superordinate in the conclusion. Moreover, AD patients resembled control subjects in judging arguments with an immediate superordinate in the conclusion compared to arguments with a distant superordinate. AD patients differed from control subjects because they could not take advantage of two premises in an argument containing basic-level concepts. We conclude that semantic knowledge is sufficiently preserved in AD to support inductive reasoning, but that limited cognitive resources may interfere with AD patients' ability to consider the entire spectrum of information available during semantic challenges.     

Quality of Life and Depression in the General Korean Population: Normative Data and Associations of the 12-Item Short Form Health Survey (SF-12) and the McGill Quality of Life Questionnaire (MQOL) with Depression (Patient Health Questionnaire-9) and Socioeconomic Status

Applied Research in Quality of Life - This study aimed to present normative data of Quality of life (QoL) and to evaluate the relationship between sociodemographic factors, multidimensional QoL and...     

The Association between Positive Parenting and Externalizing Behavior

The present study examined the role of positive parenting on externalizing behaviors in a longitudinal, genetically informative sample. It often is assumed that positive parenting prevents behavior problems in children via an environmentally mediated process. Alternatively, the association may be due to either an evocative gene-environment correlation, in which parents react to children's genetically-influenced behavior in a positive way, or a passive gene-environment correlation, where parents passively transmit a risk environment and the genetic risk factor for the behavioral outcome to their children. The present study estimated the contribution of these processes in the association between positive parenting and children's externalizing behavior. Positive parenting was assessed via observations at ages 7, 9, 14, 24, and 36 months and externalizing behaviors were assessed through parent report at ages 4, 5, 7, 9, 10, 11, and 12 years. The significant association between positive parenting and externalizing behavior was negative, with children of mothers who showed significantly more positive parenting during toddlerhood having lower levels of externalizing behavior in childhood; however, there was not adequate power to distinguish whether this covariation was due to genetic, shared environmental, or nonshared environmental influences.     

Acquisition and Automatization of a Complex Task: An Examination of Three-Ball Cascade Juggling

The learning patterns of 3-ball cascade juggling from acquisition until automaticity were examined in 10 participants. On the basis of outcome measures derived from 26 practice sessions and 4 periodic probe sessions, the authors differentiated participants into 3 distinct learning types: a proficient group, an emerging group, and a single late learner. The proficient group was distinguished by how rapidly they learned and automatized performance. Most interesting, an inverse response cost (i.e., performance boost) on the secondary task was found in the majority of proficient group members during the dual-task condition. The present results are discussed in relation to the P. L. Ackerman model (1987, 1988) of complex skill acquisition as is the significance of the inverse response cost finding.     

Efficacy of brief telephone psychotherapy with callers to a suicide hotline

The efficacy of two types of theapy conducted exclusively over the telephone was studied. Clients (N=55) were recruited from a pool of callers to a suicide hotline and were randomly assigned to a waiting list control (WC) or Solution Focused Brief Therapy (SFBT) or Common Factors Therapy (CFT). It was hypothesized that improvements would be significantly higher in the two therapy conditions compared to the waitlist control and SFBT would be significantly more efficacious than CFT. Results confirmed that improvement was significantly higher in the two treatment conditions compared to the waitlist control, but no difference in improvement was found between SFBT and CFT. The implications of these findings for suicide hotlines are discussed.     

Reward dominance and passive avoidance learning in adolescent psychopaths

This study tests predictions that adolescent psychopaths are hyperresponsive to rewards (Quay, 1988) and deficient in passive avoidance learning (Newman & Kosson, 1986). Forty male adolescent juvenile offenders were divided into psychopaths and nonpsychopaths using cluster analysis. Subjects were administered a passive avoidance learning task which required learning when to respond to cards associated with either reward or punishment. Results showed a greater responsivity to reward in psychopaths, with no group differences in passive avoidance errors. Results lend support to the view that psychopaths tend to focus on the prospect of reward under conditions of mixed incentives and, when sufficiently motivated, are capable of improved performance. Together with findings of recent psychophysiological studies, these results suggest that adolescent psychopaths may have latent abilities which could have treatment implications.The authors are greatly indebted to the boys and staff of the testing institution for their kind cooperation in this study. Thanks are also due to Dr. Rand Wilcox for statistical consultation and Cheryl Eurton and Marni Ayers for assistance in data coding.