Attention deficit hyperactivity, fetal alcohol spectrum disorder, or something else: the broad differential of...

Thomas is a 5-year 6-month-old boy whose parents requested an urgent care appointment because he has recently been suspended from kindergarten stating "and his doctor must see him before he can come back." His suspension from kindergarten was due to kicking and biting his classmates, but he has also become increasingly aggressive at home. His teacher reported that he has always had a high activity level and difficulty shifting attention between tasks, as well as noncompliance with rules and directions. He is noted to have learning challenges and is showing difficulties in the concept of numbers and letter sounds. The practice has followed Thomas since his healthy birth. He has a history of delayed language development, and he received early intervention services from 2 years of age. He spoke his first word at 2 years 6 months. He started a half-day preschool program at 3 years of age. He had difficulty acclimating to preschool, interacting with peers, and was described as "hyperactive" by his teachers. His program was modified to decrease his time having to sit in a circle time, and he often required the support of the paraprofessional in the classroom. His parents have always described him as a "difficult child." He gets frustrated easily and can tantrum for up to 2 hours multiple times in a week when his immediate needs or requests are not met. He has difficulty falling asleep, has frequent night awakenings, and often has trouble getting back to sleep. His self-help skills are poor, and he has difficulty with activities such as brushing his teeth and dressing. His parents report that he does not seem to remember rules from day to day. He was evaluated at 5 years of age and diagnosed with Attention Deficit Hyperactivity Disorder, but his response to stimulants has been limited. Thomas is an only child. His parents are college educated and professionally employed. They deny drug use, domestic violence, and guns in the home. They reported that prior to the pregnancy, they enjoyed "partying" with friends on the weekends, but Thomas's mother reported that she stopped drinking as soon as she realized she was pregnant. All are wondering whether this child might have a fetal alcohol spectrum disorder, although he seems to have no clear facial dysmorphology. It is unsure what the next step might be and if there is value added in pursuing this diagnosis. What do you do next?