Is the temperamental trait of high persistence protective in siblings? – A comparative, exploratory study of healthy siblings, and attention deficit hyperactivity disorder probands

BACKGROUND: Study of temperament in first-degree relatives is an important line of inquiry to substantiate temperament as an etiological marker. AIM: This study aims to compare temperament in children with attention deficit hyperactivity disorder (ADHD) and their healthy siblings and to assess the association between ADHD symptoms and temperament dimensions in healthy siblings. SETTINGS AND DESIGN: The study was carried out in the outpatient department of psychiatry in a tertiary care teaching hospital. A cross-sectional design with nonprobabilistic sampling technique was used for data collection. MATERIALS AND METHODS: A hundred children (50 children with ADHD and 50 siblings-one for each child with ADHD) were assessed retrospectively on temperament measurement schedule (TMS) and conners parent rating scale-revised: short form (CPRS-R: S). STATISTICAL ANALYSIS: IBM SPSS Statistics for Windows, Version 20.0 was used for statistical analysis. Mean and standard deviation and frequency and percentage were computed for continuous and categorical variables, respectively. Student’s t-test was computed to compare means of the two groups and regression analysis was computed to see for the variance in ADHD subscale scores explained by temperament scores on TMS. RESULTS: Siblings scored highest on the intensity of reaction and lowest on threshold of responsiveness. Compared to probands, siblings scored significantly higher on persistence and lower on activity level, even after controlling for gender. Persistence trait had a significant negative correlation with and explained 7.4% to 21% of variance of all CPRS-R: S subscales. Persistence and distractibility together explained 23.2% of inattention scores. CONCLUSION: Higher persistence in siblings appears to offer protection to these at-risk individuals who do not have ADHD; favoring the dual pathway model of ADHD.