The Effects of Childhood ADHD Symptoms on Early-onset Substance Use: A Swedish Twin Study

Research has documented that children and adolescents with attention-deficit/hyperactivity disorder (ADHD) are at increased risk of substance use problems. Few studies, however, have focused on early-onset substance use. This study therefore investigated how the two symptom dimensions of ADHD (hyperactivity/impulsivity and inattention) are associated with early-onset substance use, the role of persistent ADHD for the association, and to what extent the association is influenced by genetic and environmental factors. Twins (1,480 pairs) in the Swedish Twin Study of Child and Adolescent Development were followed from childhood to adolescence. ADHD symptoms were measured at age 8–9 and age 13–14 via parent-report, whereas substance use was assessed at age 13–14 via self-report. Results revealed that hyperactive/impulsive symptoms predicted early-onset “sometimes” tobacco use (adjusted odds ratios, 1.12, for one symptom count), controlling for inattentive symptoms and conduct problem behaviors. There is no independent effect of inattentive symptoms on early-onset substance use. Children with persistent hyperactivity/impulsivity (defined as scoring above the 75th percentile at both time points) had a pronounced risk of both early-onset tobacco and alcohol use (adjusted odds ratios from 1.86 to 3.35, compared to the reference group). The associations between hyperactivity/impulsivity and early-onset substance use were primarily influenced by genetic factors. Our results indicated that hyperactivity/impulsivity, but not inattention, is an important early predictor for early-onset substance use, and a shared genetic susceptibility is suggested to explain this association.     

Predictors of Boys’ ADHD Symptoms from Early to Middle Childhood: The Role of Father–Child and Mother–Child Interactions

This prospective 3 year longitudinal study investigated preschool paternal and maternal parenting predictors of Attention-Deficit/Hyperactivity Disorder(ADHD) in a community sample of 93 school-age boys. Participants were recruited on the basis of inattention-hyperactivity at age 4 and fathers and mothers were observed interacting with their sons. Teachers, fathers, and mothers reported children's ADHD symptoms and impairment. Results from dimensional analysis showed that less observed paternal sensitivity and maternal positive regard predicted higher levels of inattentiveness in middle childhood, and that intrusive paternal behavior was predictive of hyperactive-impulsive behavior at school. In categorical analysis, less maternal warmth and sensitivity were predictive of later ADHD. These predictions held after statistical adjustment for the effects of preschool ADHD behaviors and conduct problems. At follow-up, parents of boys with ADHD reported more negative child-parent relationship perceptions than comparison parents. Findings highlight the importance of examining responsive parenting behaviors of both fathers and mothers in relation to multi-informant ratings of ADHD symptoms.     

Are the pathogens of out-groups really more dangerous?

We question the plausibility of Fincher & Thornhill's (F&T's) argument that localised pathogen-host coevolution leads to out-groups having pathogens more damaging than those infecting one's own family or religious group.     

A critical evaluation of c as a measure of mnemonic resolution

It is known that visual working memory capacity is limited, but the nature of this limit remains a subject of controversy. Increasingly, two factors are thought to limit visual memory: an object-based limit associated with so-called "slots" models, and an information-based limit associated with resource models. Recently, Barton, Ester, and Awh (2009) introduced a measure of mnemonic resolution, which they dubbed c. We show here that c is critically flawed, and cannot be interpreted as a measure of resolution. We recommend strongly against its use and interpretation, and suggest alternatives approaches for researchers who want to explore mnemonic resolution.     

Bitter reproach or sweet revenge: cultural differences in response to racism

Culture has been shown to influence response styles. The authors conducted two studies to test the notion that African Americans would be more likely to respond to racism directly, whereas Asian Americans would be more likely to respond indirectly and therefore more subtly. Study 1 showed that Black women subjected to a racist comment from a confederate during an online interaction were more likely than Asian women to verbally reproach the perpetrator. These group differences were not present when the outcome measure was indirect responding--administration of good/bad jellybeans. Study 2 used an online format to demonstrate that Asian women were more likely than Black women to say they would not respond directly to a racist comment. This group difference in unwillingness to confront was significantly mediated by a goal of maintaining peace with their interaction partner. Implications of these findings for the study of discrimination, coping, and well-being are discussed.     

Arm adductor with arm abduction in rotator cuff tear patients vs. healthy--design of a new measuring instrument

The incidence of (a)symptomatic rotator cuff tears is high, but etiologic mechanisms are unclear and treatment outcomes vary. A practical tool providing objective outcome measures and insight into etiology and potential patient subgroups is desirable. Symptomatic cuff tears coincide with humerus cranialization. Adductor co-activation during active arm abduction has been reported to reduce subacromial narrowing and pain in cuff patients. We present an easy-to-use method to evaluate adductor co-activation. Twenty healthy controls and twenty full-thickness cuff tear patients exerted EMG-recorded isometric arm abduction and adduction tasks. Ab- and adductor EMG's were expressed using the "Activation Ratio (AR)" (-1 ≤ AR ≤ 1), where lower values express more co-activation. Mean control AR's ranged from .7 to .9 with moderate to good test-retest reliability (ICC: .60-.74). Patients showed significantly more adductor co-activation during abduction, with adductor AR's ranging between .3 (teres major) and .5 (latissimus dorsi). In conclusion, the introduced method discriminates symptomatic cuff tear patients from healthy controls, quantifies adductor co-activation in an interpretable measure, and provides the opportunity to study correlations between muscle activation and humerus cranialization in a straightforward manner. It has potential as an objective outcome measure, for distinguishing symptomatic from asymptomatic cuff tears and as a tool for surgical or therapeutic decision-making.     

Sexual behavior in Spanish adolescents of divorced parents

Marital breakup has been associated with numerous behavioral problems in children, such as sexual risk behaviors. This research is the first to examine sexual behaviors of Spanish adolescents related to whether their parents were married or divorced. Participants were 342 boys and girls aged between 14 and 18 years. The sample provided confidential information about their sexual behavior and birth control methods. Significant differences were only found in percentages of adolescents who had engaged in mutual masturbation, intercourse, or oral sex, and who had practiced these sexual relations in the last six months, in both cases, they were higher when the parents had broken their marital relationship. Regarding adolescents of divorced parents, engaging in intercourse is more likely in older teenagers who live with a stepparent. Moreover, older adolescents who were younger when parents divorced and who live in a reconstituted family, have more sexual partners. These and other findings are discussed.