Psych CASC / OSCE · Specialty psychiatry — sleep medicine interface
Explain delayed sleep-wake phase disorder and timed melatonin/light plan — CASC communication station
MRCPsych/FRANZCP-style communication station: reframe DSWPD as timing disorder, explain light/melatonin timing, negotiate school/uni plan, avoid colluding with open-ended hypnotics.
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Target exams
Station brief
Format. Communication station, approximately 7–10 minutes after reading. You are the psychiatry registrar in outpatient clinic. [2]
Candidate instructions. Explain delayed sleep-wake phase disorder in plain language, validate both parent concern and student experience without colluding with “laziness” stigma or indefinite strong hypnotics, outline morning light and carefully timed low-dose melatonin plus schedule change, negotiate a collaborative university return plan, and check understanding. The examiner may play parent, student, or both. [1][4][5]
Candidate scenario
Student: delayed sleep with free-day restorative late sleep; no manic features; mild low mood from failure; uses phone in bed. Parent: wants “something strong to knock them out at 22:00.” Digital light hygiene and melatonin are available; sleep medicine referral possible if needed. [1][3]
Marking domains
- Empathy and de-escalation of family conflict without dismissing either party
- Accurate plain-language model: body clock delayed, not moral failure; free-day sleep as clue [5]
- Treatment explained: fixed rise, morning light, reduce evening blue light, melatonin timed before desired bedtime (Sletten-type 0.5 mg plan) rather than random nightcap or long-term Z-drug first-line [1][3][4]
- Shared plan with university liaison and follow-up diary
- Safety-net for mood worsening; teach-back of one concrete tonight/tomorrow action
Reveal assessor key
Open. “I can see how exhausting this is for everyone. The pattern you describe — sleeping well when allowed a late schedule — fits a delayed body clock more than simple laziness or needing a stronger knockout tablet.” [5]
Model. Internal clock sits late; morning obligations hit the biological night. Phones at 02:00 push the clock later. This is treatable chronobiology. [2]
Plan. Agree a target bedtime/wake time stepwise; bright light after rising; dim screens evenings; melatonin about an hour before the desired bedtime as a clock signal (evidence supports low-dose timed melatonin with scheduling), not an unlimited sedative race. [1][3]
Parent request. Strong nightly hypnotics do not fix the clock and can create dependence; guidelines prioritise light, timing, and melatonin strategy for circadian disorders. [4]
Close. Written plan, diary, university letter, review in 2 weeks, crisis contacts if mood/SI worsens, teach-back of morning light + phone curfew. [1]
References
- [1]Sletten TL, Magee M, Murray JM, et al. Efficacy of melatonin with behavioural sleep-wake scheduling for delayed sleep-wake phase disorder: A double-blind, randomised clinical trial PLoS Med, 2018.PMID 29912983
- [2]Auger RR, Burgess HJ, Emens JS, et al. Clinical Practice Guideline for the Treatment of Intrinsic Circadian Rhythm Sleep-Wake Disorders: Advanced Sleep-Wake Phase Disorder (ASWPD), Delayed Sleep-Wake Phase Disorder (DSWPD), Non-24-Hour Sleep-Wake Rhythm Disorder (N24SWD), and Irregular Sleep-Wake Rhythm Disorder (ISWRD). An Update for 2015: An American Academy of Sleep Medicine Clinical Practice Guideline J Clin Sleep Med, 2015.PMID 26414986
- [3]van Geijlswijk IM, Korzilius HP, Smits MG The use of exogenous melatonin in delayed sleep phase disorder: a meta-analysis Sleep, 2010.PMID 21120122
- [4]Wilson S, Anderson K, Baldwin D, et al. British Association for Psychopharmacology consensus statement on evidence-based treatment of insomnia, parasomnias and circadian rhythm disorders: An update J Psychopharmacol, 2019.PMID 31271339
- [5]Sack RL, Auckley D, Auger RR, et al. Circadian rhythm sleep disorders: part II, advanced sleep phase disorder, delayed sleep phase disorder, free-running disorder, and irregular sleep-wake rhythm. An American Academy of Sleep Medicine review Sleep, 2007.PMID 18041481