Differential motor and state functioning in newborns of women on methadone

Motor and state functioning of 20 infants born to methadone-maintained women and 25 born to controls was assessed at 1 day and 1 month of age using Brazelton Neonatal Behavioral Assessment Scale with Kansas Supplements (NBAS-K). The infants were of mothers who were Black, of low SES, between the ages of 18 and 35 years, and who had good prenatal care. Motor behaviors were scored on NBAS-K items: General Tonus, Motor Maturity, and Tremulousness. State behaviors were scored on 2 items: Alertness and General Irritability. Guttman's Multidimensional Scalogram Analysis (MSA) of individual profiles revealed an orthogonal relationship between motor and state functioning, with motor functioning being a much clearer discriminator between methadone and non-methadone infants than state functioning. With age, both groups generally improved, but non-methadone infants maintained some of their advantage in motor functioning. Both groups showed a variety of behavior patterns during the neonatal period. The results suggest that methadone acts differentially on CNS functioning, with strong effects on neuro-motor functioning.