Faculty Bibliography

The literature on the prevalence and stability of preschool problems of inattention, hyperactivity, and impulsivity suggests a number of links to early literacy skills and broader school achievement. Developmental considerations in the assessment of preschool ADHD are reviewed in this paper, along with evidence for the stability of symptoms over time and the relationship between early symptoms of ADHD and elementary school achievement. Emphasis is placed on describing the nature of the connection between preschool ADHD symptoms and academic achievement, as few studies to date have focused specifically on that relationship. Several explanations for the relationship between preschool ADHD symptoms and achievement are analyzed, including an explanation that focuses on the relationship between inattention, hyperactivity, and impulsivity and the acquisition of emergent literacy and language skills. Finally, the evidence for four models that have been proposed to account for the link between behavior and learning is reviewed and critically analyzed. Suggestions are made for future research that might resolve important questions only partially addressed in studies to date.

This study investigated the role of early literacy and behavioral skills in predicting the improvement of children who have experienced reading difficulties in 1st grade. The progress of 146 low-income children whose reading scores in 1st grade were below the 30th percentile was examined to determine (a) how the poorest readers in 1st grade progressed in reading achievement through 4th grade and (b) which emergent literacy and behavioral skills measured in kindergarten predicted differential 4th grade outcomes. Results indicated that the divergence between children who improved and those who did not was established by the end of 2nd grade. Further, individual linguistic skills and behavioral attributes measured in kindergarten contributed substantively to this difference. Implications for intervention timing and educational policy are discussed.

Melanin-concentrating hormone (MCH) is a hypothalamic neuropeptide with a prominent role in feeding and energy homeostasis. The rodent MCH receptor (MCH1R) is highly expressed in the nucleus accumbens shell (AcSh), a region that is important in the regulation of appetitive behavior. Here we establish a role for MCH and MCH1R in mediating a hypothalamic-limbic circuit that regulates feeding and related behaviors. Direct delivery of an MCH1R receptor antagonist to the AcSh blocked feeding and produced an antidepressant-like effect in the forced swim test, whereas intra-AcSh injection of MCH had the opposite effect. Expression studies demonstrated that MCH1R is present in both the enkephalin- and dynorphin-positive medium spiny neurons of the AcSh. Biochemical analysis in AcSh explants showed that MCH signaling blocks dopamine-induced phosphorylation of the AMPA glutamate receptor subunit GluR1 at Ser845. Finally, food deprivation, but not other stressors, stimulated cAMP response element-binding protein-dependent pathways selectively in MCH neurons of the hypothalamus, suggesting that these neurons are responsive to a specific set of physiologically relevant conditions. This work identifies a novel hypothalamic-AcSh circuit that influences appetitive behavior and mediates the antidepressant activity of MCH1R antagonists.

A 3-year-old child was referred to consultation for hyperactivity, attention deficit, impulsivity, and sleep problems. He met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for attention-deficit/hyperactivity disorder. At baseline, the Conners' Parent Rating Scale and the Conners' Teacher Rating Scale raw total scores were 30 and 32, respectively. The child had low a serum ferritin level (13 ng/mL). After 8 months of treatment with Tardyferon (ferrous sulfate, 80 mg/day), his serum ferritin increased to 102 ng/mL. Both parents and teachers reported considerable behavioral improvement. The Conners' Parent and Teacher Rating Scale raw total scores decreased to 19 and 13, respectively. This is the first report of the effectiveness of iron supplementation in a young child with attention-deficit/hyperactivity disorder.

STUDY OBJECTIVE: To review evidence on the association between restless legs syndrome (RLS) and attention-deficit/hyperactivity disorder (ADHD), to discuss the hypothetical mechanisms underlying this association, and to consider the potential interest for common pharmacologic treatments of RLS and ADHD when co-occurring. METHOD: A PubMed search. RESULTS: In clinical samples, up to 44% of subjects with ADHD have been found to have RLS or RLS symptoms, and up to 26% of subjects with RLS have been found to have ADHD or ADHD symptoms. Several mechanisms may explain this association. Sleep disruption associated with RLS might lead to inattentiveness, moodiness, and paradoxical overactivity. Diurnal manifestations of RLS, such as restlessness and inattention, might mimic ADHD symptoms. Alternatively, RLS might be comorbid with idiopathic ADHD. Subjects with RLS and a subset of subjects with ADHD might share a common dopamine dysfunction. Limited evidence suggests that some dopaminergic agents, such as levodopa/carbidopa, pergolide, and ropinirole, may be effective in children with RLS associated with ADHD symptoms. CONCLUSIONS: Although still limited, evidence from clinical studies demonstrates an association between RLS and ADHD or ADHD symptoms. Further clinical studies using standard criteria and procedures are needed to better estimate the degree of association. Epidemiologic studies are required to assess the relationship between ADHD and RLS symptoms in nonclinical samples. Further investigations should address the mechanisms underlying the relationship between RLS and ADHD. Several dopaminergic agents seem to be promising treatment for RLS associated with ADHD symptoms. To date, however, the absence of randomized and blinded controlled studies does not allow evidence-based recommendations.