A longitudinal study of offspring born to methadone-maintained women. II. Dyadic interaction and infant behavior at 4 months.

As part of a longitudinal study of offspring born to substance abusers, we assessed 17 methadone-exposed and 23 comparison 4-month-old infants using the Bayley Scales, and videotaped their interaction with their mothers. In analyzing the Bayley Infant Behavior Record we found that the methadone-exposed group differed from the comparison group on motor functioning but not significantly on social or cognitive behaviors; methadone-exposed infants were more tense, active, and poorly coordinated than comparisons. Using a scale we developed, we rated communicative functioning in dyadic interactions, and related mothers' interactive performance to their psychological and psychosocial resources and infants' interactive performance to their behavioral functioning as assessed on the Bayley Infant Behavior Record. Applying a multidimensional technique, Guttman's Partial Order Scalogram Analysis by Coordinates (POSAC), we found an intriguing relationship that generalized across drug and comparison groups: greater tension than activity, with high tension especially, related to poorer functioning, but tension lower than activity related to better functioning. Specifically, infants who were tense and not active were also poorest on social functioning (low responsiveness to people and low cooperativeness) and showed short attention span and low persistence combined with high interest in sights and sounds. On the other hand, infants who showed low-to-moderate tension and moderate-to-high activity were highly responsive and cooperative; some also had long attention span and high persistence coupled with interest in sights and sounds. Infants who were both very tense and very active were poor on social functioning. Furthermore, most infants with tension higher than activity did poorly in communicating with their mothers, while infants with tension lower than activity interacted well. The POSAC technique has enabled us to identify meaningful subgroups of infants who were not merely quantitatively but qualitatively different in their behavioral functioning. Cutting across drug and comparison groups, we found that mothers who performed poorly on interaction were likely to have poor resources for maternal functioning. Methadone was only one among the risk factors affecting interaction.