In this case report we describe how a 13-year-old boy with a complex development profile was diagnosed with adhd and who was also found to have a megacisterna magna, a posterior fossa anomaly in the Dandy-Walker continuum. We searched the literature for reports of other patients who had this (mild) brain anomaly along with psychiatric problems in general and attention problems in particular. Our search of the literature suggested a possible link between the two diagnostic entities.