Attention deficit hyperactivity disorder predominantly inattentive (ADHD-PI or ADHD-I),[3] is one of the three presentations of attention deficit hyperactivity disorder (ADHD).[4] In 1987–1994, there were no subtypes or presentations and thus it was not distinguished from hyperactive ADHD in the Diagnostic and Statistical Manual (DSM-III-R). In DSM-5, subtypes were discarded and reclassified as presentations of the same disorder that change over time.
The 'predominantly inattentive presentation' is similar to the other presentations of ADHD except that it is characterized predominately by symptoms of inattention, such as poor sustained attention, procrastination, hesitation, and forgetfulness. It differs in having fewer or no typical symptoms of hyperactivity or impulsiveness. Lethargy and fatigue are sometimes reported, but ADHD-PI is separate from the distinct cognitive disengagement syndrome (CDS).[5]