The parents of a 14-year-old female high school freshman bring her to the PMHNP for an evaluation. They believe she should be doing better in high school due to her "gifted" status. They state that she has a formal IQ score of 125 and that her grades were mostly As through 5th grade. Now, she hands in her papers late and her grades are dropping to mostly Bs and Cs. During her psychiatric evaluation, the girl reports that high school is different from elementary school and junior high because now she has to write papers. She says she often turns them in late due to procrastination and forgetfulness. She reports a long history of inability to sustain attention while in class or doing homework, failure to pay attention to details or finish chores or tasks, significant difficulties with time management, planning, and organization. She is forgetful, often loses things, and is easily distracted. She has no history of restlessness or impulsivity, and she is popular with her peers. What is the most likely diagnosis?

Choice A reason: Anxiety disorder may cause difficulties in concentration and performance, but it does not typically explain the lifelong pattern of inattention, procrastination, and forgetfulness that is consistent across settings and tasks. Choice B reason: Specific learning disorder affects academic skills such as reading, writing, or mathematics. While it may contribute to academic challenges, it does not fully account for the pervasive inattentiveness, organizational deficits, and difficulty sustaining focus observed in this patient. Choice C reason: Attention-deficit hyperactivity disorder, predominantly inattentive type, is characterized by a long-standing pattern of inattention without hyperactivity or impulsivity. Symptoms such as forgetfulness, losing items, difficulty sustaining attention, and organizational challenges align with this patient’s presentation, making it the most likely diagnosis. Choice D reason: Disruptive mood dysregulation disorder is primarily characterized by severe irritability and frequent temper outbursts. The patient does not present with mood dysregulation or behavioral outbursts, making this diagnosis unlikely.