The Toddler Who Won't Eat and the Teen Who Won't Sleep
A parent describes two children. Child A, age 2, used to say 40+ words; over 6 weeks she has stopped using most words, avoids eye contact, repeats phrases from videos verbatim, and lines up toys instead of pretending. She does not respond to her name but does turn when a wrapper crinkles. Child B, age 15, goes to bed at 2 a.m. and wakes at 6 a.m. for school, naps 3 hours after school, and has become irritable and grades have slipped. He insists on the nap and says he 'can't fall asleep' at night. The parent asks whether Child A is 'just a late talker' and whether Child B should be given melatonin by the parent without a clinician.
1. For Child A, identify the features that argue against 'late talker' and name the pattern. What developmental concept explains the loss of previously acquired words?
Read the worked answer
Arguments against a simple language delay:
- Regression: she had 40+ words and lost them - loss of previously acquired skills is a red flag, not typical of late talkers.
- Social-communication deficits: reduced eye contact, no response to name (while responding to a non-social sound - wrapper - argues against simple hearing loss).
- Repetitive behavior and echolalia: verbatim repetition, lining up toys, absence of pretend play.
The pattern is consistent with autism spectrum disorder features. The relevant concept is developmental regression - loss of skills after a period of typical development - which warrants prompt professional evaluation rather than watchful waiting. Note: the wrapper response suggests auditory detection is intact, but a hearing evaluation is still standard. Diagnosis requires a clinician; the case supports referral, not a label.
2. For Child B, explain the likely mechanism maintaining the sleep problem and why the after-school nap may worsen it.
Read the worked answer
This is a delayed sleep–wake phase pattern with a reinforcement loop: he cannot fall asleep at a typical hour (phase delay, common in adolescence partly due to circadian shift), so he is sleep-deprived, takes a long after-school nap, and the nap reduces homeostatic sleep pressure at bedtime, making 2 a.m. sleep onset more likely. The nap is negatively reinforced (relieves fatigue), so it persists.
Mechanism names: circadian rhythm shift (phase delay), sleep pressure/homeostatic drive, and negative reinforcement maintaining the nap. Irritability and grade decline are consistent with chronic insufficient sleep affecting attention and mood.
Implication: the nap is not the root cause but a maintaining factor; shortening/eliminating it and shifting bedtime gradually (with light exposure in the morning) addresses the loop.
3. The parent asks for a decision rule: when to act now versus watch and wait, for each child.
Read the worked answer
A defensible rule: regression, loss of function, or safety risk → act now (refer).
- Child A: regression plus social-communication red flags → prompt evaluation (developmental/audiological). Watchful waiting is inappropriate when skills are lost.
- Child B: no acute safety emergency described, but chronic sleep restriction with functional impairment (grades, mood) → bring to a clinician rather than parent-initiated melatonin, because melatonin is a hormone with dosing/timing considerations and can be contraindicated; behavioral sleep measures are first-line and need guidance.
General principle: distinguish variation (wide range of normal development) from deviation (loss of skills, failure to gain, functional impairment). The presence of regression or impairment shifts the decision from monitoring to referral. The parent should not self-prescribe; the exam-relevant judgment is recognizing when the pattern exceeds normal variation.