A 9-year-old boy is referred for evaluation. He shows marked difficulty organizing tasks, loses things frequently, and forgets instructions. He sits quietly in class but daydreams constantly. His parents report no hyperactivity. Which feature most clearly distinguishes his presentation from ADHD Predominantly Hyperactive-Impulsive Type?

Explanation

## ADHD Inattentive vs. Hyperactive-Impulsive Type ### Clinical Presentation Contrast **Key Point:** The case describes a child with prominent inattention (disorganization, forgetfulness, daydreaming) but NO hyperactivity or impulsivity. This is the defining feature of Predominantly Inattentive Type. ### Symptom Profile Comparison | Symptom Domain | Inattentive Type | Hyperactive-Impulsive Type | |---|---|---| | **Inattention** | ≥6 symptoms present | <6 symptoms | | **Hyperactivity-Impulsivity** | <6 symptoms | ≥6 symptoms | | **Typical presentation** | Quiet, daydreaming, disorganized | Fidgety, restless, interrupts, blurts | | **School behavior** | Appears lazy or unmotivated | Disruptive, can't stay seated | | **Recognition** | Often missed; labeled "spacey" | Easily identified; referred early | ### Why This Child Has Inattentive Type **High-Yield:** The absence of hyperactivity and impulsivity symptoms (≥6 required for Hyperactive-Impulsive Type) combined with clear inattention symptoms is the single best discriminator. This child does NOT meet threshold for hyperactivity-impulsivity. **Clinical Pearl:** Inattentive Type is frequently underdiagnosed because: - Children are not disruptive ("good" behavior masks symptoms) - Teachers may not refer them - Parents may attribute symptoms to laziness or low motivation - Daydreaming is often normalized as "being a dreamer" ### Why Other Options Don't Discriminate - **Executive dysfunction:** Present in both types; not specific to Inattentive Type - **Daydreaming:** A manifestation of inattention, but not the defining discriminator between subtypes - **Age of presentation:** Both subtypes present in childhood; not discriminating [cite:DSM-5 ADHD Criteria; Barkley ADHD in Children]