Externalizing Problem Behaviour and its Relation to the Self-Regulation of Emotion in Children Prenatally Exposed to Methadone: Outcomes at Age 9.5 Years
Degree GrantorUniversity of Canterbury
Degree NameMaster of Science
The only approved option for treating opiate dependency during pregnancy in New Zealand is Methadone Maintenance Therapy and while the benefits of this treatment for the mother are well established, the long term impact of prenatal methadone exposure for the child remains unclear. The current study is the first of its kind to investigate the relative contribution of prenatal methadone exposure, self-regulation of emotion, poly-substance exposure and socio-environmental risk factors to behavioural adjustment in children at age 9.5 years. As part of a prospective longitudinal study, fifty methadone exposed (ME) children and fifty non-exposed (Non-ME) comparison children were assessed using a range of laboratory based tasks and parent-report measures. Pre and postnatal socio-environmental and drug-use risk factors were measured via a comprehensive developmental interview conducted with each child’s caregiver. Behavioural adjustment was assessed using the Behavioural Assessment System for Children – Second Edition (BASC-2), while effortful control (a component of effective self-regulation) was assessed using the Frustrating Puzzle Box and Stop-Signal tasks.
At age 9.5 years, ME children were rated by their caregivers as exhibiting a higher level of externalizing behavioural problems than Non-ME children both in overall score (p<.001), and in the proportion of children whose scores classified them as having an at-risk (p<.001) or clinically significant (p=.002) level of disruptive or maladaptive behaviour. On closer examination, ME children were found to score significantly higher than Non-ME children on the Conduct Problems, Attention Problems and Hyperactivity scales (p<.001), as well having a higher rate of co-morbidity between behavioural problems (p<.001). In addition to behavioural adjustment difficulties at age 9.5 years, ME children also scored significantly lower on a composite measure of effortful control (p<.001), indicating deficits in self-regulatory ability. Following regression analysis, prenatal methadone exposure (p<.001) and socio-environmental risk (p=0.04) were found to significantly contribute to externalizing problem behaviour scores over and above the effects of poly-substance exposure during pregnancy and effortful control ability, highlighting the importance of considering multiple risk factors in any research involving ME participants.
The findings of the current study contribute unique information to the limited existing literature on long term developmental outcomes for ME children and support the continued follow-up and assessment of this population. Impaired effortful control ability and high rates of externalizing behavioural problems identify two areas of vulnerability in which ME children and their families may require additional support to manage difficulties associated with these issues. Identifying the areas in which ME children are performing poorly compared to their Non-Exposed peers will allow for more targeted interventions to be implemented and enable ME children to remain on a positive developmental trajectory.