A 6-year-old girl with Autism Spectrum Disorder is being assessed for associated features and comorbidities. Which of the following is NOT typically associated with or considered part of the autism spectrum phenotype?

Explanation

## Associated Features & Comorbidities in Autism Spectrum Disorder **Key Point:** While individuals with ASD frequently experience mood symptoms and may have co-occurring mood disorders, episodic rapid cycling mood swings (euphoria to dysphoria) without environmental trigger is characteristic of **Bipolar Disorder**, not ASD. ### Core & Associated Features of ASD | Feature | Status in ASD | Notes | |---------|---------------|-------| | **Sensory sensitivities** | Core associated feature | Hyperresponsiveness (aversion to lights, sounds, textures) or hyporeresponsiveness (seeking intense stimulation) | | **Repetitive motor movements** | Core restricted behavior domain | Stereotypies, stimming, hand flapping, spinning, lining up objects | | **Insistence on sameness & routine** | Core restricted behavior domain | Distress with changes; preference for predictability | | **Rapid mood cycling (no trigger)** | NOT typical of ASD | Characteristic of Bipolar Disorder; if present, suggests comorbid mood disorder | ### Mood Presentation in ASD vs. Bipolar Disorder **Clinical Pearl:** Children with ASD may experience mood dysregulation, anxiety, and irritability—often triggered by sensory overload, social stress, or disruption of routine. However, the rapid, unprovoked cycling between euphoria and dysphoria seen in Bipolar Disorder is **not** a core feature of ASD. When such cycling occurs in a child with ASD, it suggests a separate comorbid diagnosis. **High-Yield:** The distinction is important: ASD mood changes are typically **reactive** (to environmental or sensory triggers), whereas Bipolar Disorder mood episodes are **episodic and endogenous** (arising without clear external cause). ### Common Comorbidities in ASD - Anxiety disorders (most common) - ADHD - Intellectual disability (30–50% of cases) - Seizure disorders - Sleep disorders - Gastrointestinal disorders - OCD and other obsessive-compulsive spectrum conditions **Warning:** Do not confuse restricted interests and repetitive behaviors in ASD with the obsessive-compulsive symptoms of OCD, though they can co-occur. In ASD, these behaviors are ego-syntonic (the child finds them comforting); in OCD, they are ego-dystonic (the child experiences them as distressing). [cite:DSM-5 Neurodevelopmental Disorders; Harrison 21e Ch 387]