Familiärer Stress und Symptome der Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung bei Vorschulkindern

Background: Attention deficit/hyperactivity disorder (ADHD) is regarded as a neurodevelopmental disorder. Executive inhibitory control and delay of gratification constitute ADHD-related neuropsychological basic deficits, that may indicate “causal pathways” to ADHD. Moreover, current theorizing points to vulnerability/transaction processes that might be involved in some of the causal pathways leading to ADHD. Thus, deficits in inhibitory control and delay of gratification might increase the probability of developing ADHD symptoms under psychosocial risk conditions. Among the ADHD-related psychosocial risk factors, maternal depression and interparental conflict have been shown to be the most closely associated with ADHD. Psychosocial stress has been conceptualized as a trigger for ADHD and as a factor that influences the course of the disorder. Hair cortisol concentration is considered as a biomarker of prolonged stress (several months). To date, there are no studies on ADHD symptoms, basic deficits, and hair cortisol concentration. The aim of this dissertation is to analyze whether inhibitory control and delay of gratification act as moderator variables of the association between these psychosocial risks (and hair cortisol concentration respectively) and ADHD symptoms in preschool children. Methods: The sample consisted of n=206 families with four- to five-year- old children. Hair samples were taken from n=126 children. The sample was enriched with preschoolers who exceeded the 70th percentile of an ADHD screening questionnaire (FBB-ADHS-V) and children whose sibling is or was 139 affected by ADHD. ADHD symptoms were assessed by a clinical interview with parents and questionnaires filled in by parents and nursery teachers. Maternal depressive symptoms were assessed by a self-rating questionnaire; interparental conflict was assessed by a questionnaire filled in by mothers and fathers. For determination of long-term cortisol exposure, 3cm of scalp hair were used. Inhibitory control and delay of gratification were determined by a set of neu- ropsychological tasks. Intelligence level was estimated by two subtests of an intelligence test. Comorbid oppositional, anxious, and depressive symptoms were assessed by questionnaires. Maternal ADHD symptoms were assessed by a questionnaire and a structured clinical interview. Results: After controlling for maternal ADHD symptoms and education level, and for gender, intelligence, anxiety/depressive and oppositional symptoms of the child, none of the interaction effects using inhibitory control as a moderator variable proved to be statistically significant. The interaction effects between delay of gratification and maternal depressive symptoms, interparental conflict as well as hair cortisol concentration were statistically significant. For children with delay of gratification deficits, high ADHD symptoms were associated with high maternal depressive symptoms, high interparental conflict and high hair cortisol concentrations. For children without these deficits, the association was not significant. Conclusions: The findings are in line with the assumption that the neuropsychological basic deficit delay of gratification predisposes the child to develop ADHD symptoms under psychosocial high-risk conditions. Delay of gratification might be regarded as an early-developing vulnerability marker, indicating one causal pathway that involves transaction processes with environmental risk factors. The constellation ’low delay of gratification/high hair cortisol concentration’ might reflect a specific ADHD subtype, which requires further investigation.