Development of Speed, Memory, and Fluid Reasoning in Children

Children\u27s memory and higher-order cognitive abilities such as fluid reasoning improve with age, but the relationships between these abilities are not well understood. The developmental cascade model proposed by Fry and Hale: 1996) suggests that age related improvements in speed of processing are related to improvements in working memory, which in turn influence fluid reasoning. Recent research in adults suggests secondary memory is also an important predictor of fluid reasoning. The relations between working memory and fluid reasoning have been studied extensively in both adults and children. However, the relationships between working memory, secondary memory, and fluid reasoning have not been simultaneously examined in children. In this study 113 children: 6 to 12 years of age) completed a battery of cognitive tests including speed of processing, working memory, secondary memory, and fluid reasoning. Correlation, regression, and path analyses were used to better understand the relationships between working memory, secondary memory, and fluid reasoning. Results indicated that only working memory accounted for significant unique variance in predicting fluid reasoning in children. Secondary memory influenced fluid reasoning indirectly by mediating the relations between speed and working memory

Nonverbal Reasoning in Preschool Children: Investigating the Putative Risk of Secondhand Smoke Exposure and Attention-Deficit/Hyperactivity Disorder as a Mediator

Exposure to secondhand smoke (SHS) has been found to be associated with cognitive deficits in children. However, relatively little is known about the relationship between SHS exposure, cognitive deficits, and smoking-related psychopathology, specifically attention-deficit/hyperactivity disorder (ADHD) and externalizing disorders such as conduct disorder (CD) and oppositional defiant disorder (ODD) in preschool children.Children (n = 54) between the ages of 4 and 6 years from a comprehensive, longitudinal study of preschool emotional development were included in this study. Each child's primary caregiver completed questionnaires and interviews related to childhood psychopathology. SHS exposure was estimated with the use of saliva cotinine values.After adjustment for sociodemographic factors (e.g., age, gender, an income-to-needs ratio) and for ADHD, CD, and ODD symptoms, exposure to SHS was found to be negatively associated with preschool children's nonverbal reasoning skills. Exposure to SHS continued to be negatively associated with nonverbal reasoning skills after adjustment for maternal education, maternal smoking during pregnancy, and maternal reports of exposure to SHS during pregnancy in separate models.Children who grow up in an environment with adults who smoke are vulnerable to several social and environmental risk factors. The findings of this study suggest that exposure to SHS during early childhood should also be considered as a potential variable in the risk trajectory and as a marker of other associated risks when formulating public health intervention and prevention strategies

Attention-deficit/hyperactivity disorder subtypes and substance use and use disorders in NESARC

BACKGROUND: Attention-deficit /hyperactivity disorder (ADHD) is associated with substance use and substance use disorders (SUD). However, relatively little is known about the relationship between DSM-IV ADHD subtypes and substance use or DSM-IV abuse/dependence in epidemiological samples. METHODS: Data were obtained from the National Epidemiologic Survey of Alcohol and Related Conditions (NESARC, N=33,588). Respondents reported on ADHD symptoms (DSM-IV) for the period of time when they were 17 years or younger. Lifetime use and DSM-IV abuse/dependence of alcohol, nicotine, cannabis, cocaine, sedatives, stimulants and heroin/opiates were compared across those with ADHD symptoms but no diagnosis (ADHDsx; N=17,009), the Combined (ADHD-C; N=361), Predominantly Inattentive (ADHD-I; N=325), and the Predominantly Hyperactive-Impulsive (ADHD-HI; N=279) ADHD subtypes. Taking a more dimensional approach, inattentive and hyperactive-impulsive symptom counts and their associations with substance use and misuse were also examined. RESULTS: After adjustments for conduct disorder, major depressive disorder, any anxiety disorder and other socio-demographic covariates, substance use and SUD were associated with ADHDsx, ADHD-C, ADHD-I and ADHD-HI. Overall, substance use and SUD were more weakly associated with the ADHDsx group compared to the three ADHD diagnostic groups. Statistically significant differences were not evident across the three diagnostic groups. Hyperactive-impulsive symptoms were more consistently associated with substance use and SUD compared to inattentive symptoms. CONCLUSIONS: ADHD subtypes are consistently associated with substance use and SUD. The relatively stronger association of hyperactive/impulsive symptoms with substance use and abuse/dependence is consistent with the extant literature noting impulsivity as a precursor of substance use and SUD

ADHD Symptoms, Autistic Traits, and Substance Use and Misuse in Adult Australian Twins

Objective: Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder frequently co-occur. Several studies show increased risk of substance use disorders in ADHD, yet there is limited information related to how ADHD symptoms, autistic traits, and their combined effects are associated with nicotine, alcohol, and cannabis use and use disorders in the general population. Method: Cross-sectional interview and self-report questionnaire data from 3,080 young adult Australian twins (mean age 31.9 years) were used to assess ADHD symptoms, autistic traits, substance use, and substance use disorders. Substance use disorders based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria were assessed in the full sample as well as in those who reported substance use. Logistic regression analyses were used for comparing the associations between ADHD symptoms, autistic traits, substance use, and substance misuse after conduct disorder, sex, age, and zygosity were controlled for. Results: Greater ADHD symptoms and autistic traits scores were associated with elevated levels of regular smoking; cannabis use; and nicotine, alcohol, and cannabis use disorders, even after conduct disorder was adjusted for. In contrast, for alcohol use, those with high autistic traits scores were less likely to report drinking to intoxication. However, upon initiation, and similar to the findings for nicotine and cannabis, they were at elevated risk for developing alcohol dependence. Conclusions: Increased liability to ADHD and elevated autistic traits scores were associated with substance use and misuse, with the exception of alcohol use. Given the social underpinnings of drinking, persons with autistic traits may be less likely to engage in it; however, upon engagement in drinking, their vulnerability to alcohol dependence is elevated