ABSTRACT
INTRODUCTION: The purpose of this longitudinal study was to investigate the relationship between the 5-HTTLPR genotype, symptoms of ADHD in adolescence and adulthood, and educational attainment in a population representative sample. Neuroticism, depressive symptoms and general mental abilities were controlled for as possible confounding factors. METHODS: ADHD symptoms were reported at age 15 and 18 by teachers using the Hyperactivity Scale of af Klinteberg and SNAP-IV, and self-reported at age 25 using the ASRS. Data about education were reported at age 25. RESULTS: At age 15, subjects with the l/l genotype had more concentration difficulties compared to s-allele carriers, and they also had more inattention symptoms according to SNAP-IV at age 18. These results were not altered by taking neuroticism or depressive symptoms into account. No 5-HTTLPR genotype effect on self-reported ADHD symptoms at age 25 was found. Inattention symptoms in adolescence were associated with lower education in young adulthood. The proportion of subjects with higher education at age 25 was significantly larger among s/s genotype compared to the l/l or s/l genotype. CONCLUSIONS: The l/l genotype of the 5-HTTLPR is associated with inattentive symptoms during adolescence in the general population, and increases the likelihood of inferior educational level in young adulthood.
Subject(s)
Achievement , Attention Deficit Disorder with Hyperactivity/genetics , Attention , Promoter Regions, Genetic , Serotonin Plasma Membrane Transport Proteins/genetics , Adolescent , Adult , Alleles , Attention Deficit Disorder with Hyperactivity/diagnosis , Educational Status , Female , Genotype , Humans , Longitudinal Studies , Male , Personality , Polymorphism, Single NucleotideABSTRACT
1. The effect of gender, smoking and pubertal development on platelet monoamine oxidase (MAO) activity was described in a randomly selected, large sample of 9- and 15-years old healthy children. 2. Platelet MAO activity was measured in 1129 children by a radioenzymatic method with beta-phenylethylamine as the substrate. Smoking habits were reported in an anonymous questionnaire. Pubertal status was assessed visually using Tanner's stages. 3. Boys, younger children and smokers had significantly lower platelet MAO activity than girls, older children and non-smokers, respectively. Girls in Tanner's stage V for breast and pubic hair development had significantly lower MAO than girls in stage IV. 4. Differences in gender, age, pubertal status and smoking habits must be taken into account if the relationship between platelet MAO activity, personality and psychiatric disorders is studied in children.
