Objective: To examine the effects of treatment sequence of parent stimulant medication (MED) and behavioral parent training (BPT) on child, maternal, and parenting outcomes among multiplex attention-deficit/hyperactivity disorder (ADHD) families using a pilot Sequential Multiple Assignment Randomized Trial (SMART) design.

Methods: To be eligible, mothers had to meet DSM-IV diagnostic criteria for ADHD, and their children had to have elevated ADHD symptoms. Thirty-five mother-child dyads were randomized at baseline and again at week 8. The resulting 4 sequences were MED MED, BPT-BPT, MED-BPT, and BPT MED. Outcomes included child ADHD symptoms, child impairment, maternal ADHD symptoms, and parenting at week 16. Data were collected from September 2012 to December 2016.

Results: The BPT-MED sequence demonstrated the most favorable outcomes for child ADHD symptoms (effect size= -0.36) and child impairment (effect sizes -0.33 to -0.51). All 3 sequences involving medication demonstrated similar impact on maternal ADHD symptoms (effect sizes ranged from -0.32 to -0.48). The BPT-MED (effect sizes ranged from 0.30 to 0.35) had the most favorable effects on positive parenting outcomes. For negative parenting outcomes, BPT-MED (effect size= -0.50 for self report) and BPT-BPT (effect size= -0.08 for observation) had the most favorable outcomes.

Conclusions: Overall, based on this pilot SMART, combination treatment may be helpful for most multiplex ADHD families, and sequencing treatments with BPT first followed by stimulant medication for the mother may be the most promising approach to improve child ADHD symptoms, impairment, and parenting. These results require replication with a fully powered SMART design. We conclude with considerations for implementing a model of care for multiplex ADHD families.