Suspected narcolepsy type 1 with near-miss driving and cataplexy (MEQ)

(i) Formulation. Working diagnosis: narcolepsy type 1 — chronic EDS with emotion-triggered cataplexy, hypnagogic hallucinations, sleep paralysis, and disrupted restorative quality despite adequate time in bed. Comorbid residual depressive symptoms possible, but sleepiness is not explained by sertraline non-response alone. Differentials: behaviourally induced insufficient sleep (less likely given 8–9 h), OSA (low pretest but still screen), medication/substance sedation, idiopathic hypersomnia (cataplexy argues against), atypical depression hypersomnia, seizure/syncope mimics of collapse (consciousness preserved argues for cataplexy), secondary hypothalamic disease if red flags.[1][2]

(ii) Assessment/investigations. Structured hypersomnolence history and ESS; collateral; mood/suicide risk; full medication list. Advise temporary driving cessation pending assessment per jurisdiction. Sleep medicine referral for nocturnal PSG then MSLT after documenting adequate sleep opportunity; address OSA if present before final interpretation. Classic MSLT support: mean latency typically 8 minutes or less with 2 or more SOREMPs. Consider CSF hypocretin-1 if available/indicated; HLA-DQB1*06:02 is supportive only. Baseline BP before wake promoters; pregnancy status if relevant.[5][1][4]

(iii) Management. Non-drug: scheduled strategic naps, regular schedule, university accommodations, safety planning for cataplexy (cooking/swimming). EDS: modafinil-class first-line where licensed (e.g. modafinil commonly 100–200 mg oral morning, titrate toward 200–400 mg/day as tolerated with BP/anxiety monitoring) or alternatives (solriamfetol, pitolisant, stimulants selected).[3][4] Cataplexy: sodium oxybate controlled protocol if accessible (never with alcohol/sedatives) and/or REM-suppressing antidepressant anticataplectics (e.g. venlafaxine/clomipramine teaching) coordinated with current sertraline plan to avoid stacking risk and abrupt rebound.[8][3][2] Review mood treatment in parallel — do not assume SSRI alone treats sleep attacks.

(iv) Driving and psychiatry. Document fitness-to-drive discussion and near-misses; occupational/university safety. Integrate depression care, avoid mislabeling hypnagogic phenomena as primary psychosis, and plan shared care with sleep medicine. Safety-net for escalating near-misses, injury, or suicidal ideation.[4][1]

(v) Pathophysiology. NT1 reflects selective loss of hypothalamic orexin/hypocretin neurons with low CSF hypocretin-1, destabilising wake and allowing REM atonia phenomena (cataplexy) into wakefulness; autoimmune framing including HLA risk and post-infectious/vaccine associations may be mentioned at viva depth.[6][7][1]