Educational Disclaimer: This case study is for educational and informational purposes only. It does not constitute medical advice, clinical guidance, or a substitute for professional psychiatric evaluation. All diagnostic criteria referenced are from the DSM-5-TR (APA, 2022). Clinicians should rely on their professional training, direct patient assessment, and current evidence-based guidelines when making diagnostic and treatment decisions.

Clinical Vignette

Patient: "Mr. H," 69-year-old retired accountant, self-referred after noticing he is 'not as sharp as I used to be' over the past year.

Chief Concern: "I've been forgetting names more often, misplacing my reading glasses daily, and I had trouble with my taxes for the first time — I always did them myself. I still manage everything, but it takes more effort. Am I getting dementia?"

History of Present Illness: Mr. H reports a 12-month history of subjective cognitive concerns. Specific complaints: increased word-finding pauses ('names are on the tip of my tongue'), misplacing objects (glasses, keys, wallet — daily), difficulty completing his tax return (previously effortless — this year took 3 times longer and he made 2 errors he caught on review), and needing to re-read paragraphs he previously would comprehend in a single pass. Critically, he REMAINS INDEPENDENT: he manages his finances (with more effort), drives safely, cooks, manages medications, and maintains his social schedule. His wife confirms the changes are real ('he's definitely slower') but also confirms he handles everything himself. He uses compensatory strategies: lists, calendar reminders, placing keys in a designated spot. MoCA score: 23/30 (lost points: delayed recall 3/5, Trail B equivalent 0/1, fluency 0/1). MMSE: 27/30 (less sensitive to mild impairment).

Medical History: Hypertension (controlled). No diabetes. No stroke. No TBI. Vitamin B12 and TSH: normal.

Mental Status Exam: Well-groomed, articulate. Speech fluent with occasional word-finding pauses. Mood 'concerned.' Affect appropriate. Describes his cognitive changes with precision and self-awareness. No depression. No psychotic symptoms. MoCA 23/30. Clock Drawing: correct (intact visuospatial). Insight excellent.

Step 1: Mild NCD DSM-5-TR Criteria

Criterion A: Evidence of MODEST cognitive decline from a previous level in ≥1 domain based on: (1) concern of the individual, informant, or clinician; AND (2) a MODEST impairment in cognitive performance, preferably documented by standardized testing.

(1) Patient concerned ('not as sharp'). Wife confirms changes. (2) MoCA 23/30 (borderline; below expected for educational level). Specific deficits in delayed recall (3/5) and executive function (Trail B equivalent 0/1). Decline from prior level confirmed by informant. MET — MODEST decline documented.

Criterion B: Cognitive deficits DO NOT interfere with capacity for independence in everyday activities.

Manages finances (with more effort). Drives. Cooks. Manages medications. Social schedule maintained. Uses compensatory strategies (lists, calendar). Independence PRESERVED. MET — INDEPENDENCE PRESERVED.

Criterion C: Not during delirium. Criterion D: Not better explained by another mental disorder.

Chronic (12 months). Not delirium. No depression. Reversible causes excluded (B12, TSH normal). MET.

Step 2: Mild NCD vs. Normal Aging vs. Major NCD

Feature Normal Aging Mild NCD Major NCD This Patient
Cognitive change Subjective, minimal objective Objective decline (documented on testing) Significant decline (multiple domains) Mild NCD: MoCA 23/30, documented deficits
Functional impact None Preserved independence (may use compensatory strategies) Loss of independence Mild NCD: independent with compensatory strategies
Self-awareness Aware of normal slowing Aware and concerned Often reduced (anosognosia) Excellent self-awareness
Informant report 'Normal for age' 'Definitely changed' 'Can't manage anymore' 'Definitely slower'
Progression risk Low 10-15% per year convert to Major NCD Not applicable (already major) Monitoring indicated

Watchful Monitoring

Mr. H meets criteria for Mild NCD: objective cognitive decline with PRESERVED independence. This places him at elevated risk for progression to Major NCD. Annual cognitive monitoring with standardized testing is indicated to detect progression early.

Diagnostic Formulation

Diagnostic Conclusion

Mild Neurocognitive Disorder, Uncertain Etiology (G31.84): All DSM-5-TR criteria met. Modest cognitive decline in learning/memory and executive function. Independence PRESERVED (with compensatory strategies). Reversible causes excluded (B12, TSH normal). Etiology: uncertain at this stage (may be prodromal Alzheimer's, vascular, or non-progressive). Treatment: (1) Lifestyle interventions (physical exercise, cognitive engagement, Mediterranean diet — all have evidence for slowing cognitive decline). (2) Vascular risk factor management (hypertension control). (3) Annual cognitive monitoring (MoCA or equivalent). (4) Biomarker evaluation if progression occurs or patient/family desires (amyloid PET, CSF Aβ/tau). No cholinesterase inhibitors indicated at the mild NCD stage.

Teaching Points

  • The distinction between Mild NCD and Major NCD is FUNCTIONAL INDEPENDENCE (Criterion B). In Mild NCD, the patient manages daily activities independently (though possibly with more effort or compensatory strategies). In Major NCD, the patient has LOST independence and requires assistance. This single criterion determines the diagnostic category.
  • Mild NCD (formerly termed Mild Cognitive Impairment/MCI) carries a conversion rate to Major NCD of approximately 10-15% per year, depending on the underlying etiology. However, some patients remain stable for years, and a proportion return to normal cognition. Mild NCD is NOT an inevitable step toward dementia.
  • Compensatory strategies (lists, calendar reminders, designated placement of items) are a hallmark of Mild NCD. Patients retain enough cognitive capacity and insight to develop workarounds for their deficits. The ability to generate and USE compensatory strategies is itself evidence of preserved executive function.
  • Cholinesterase inhibitors are NOT recommended for Mild NCD. Clinical trials have not demonstrated benefit at this stage. Treatment focuses on lifestyle modification: physical exercise (aerobic, 150 minutes/week), cognitive engagement, social activity, Mediterranean diet, and vascular risk factor management.
  • The MoCA (Montreal Cognitive Assessment) is more sensitive than the MMSE for detecting Mild NCD, particularly for executive function and attention deficits. Mr. H's MMSE was 27/30 (potentially 'normal') while his MoCA was 23/30 (clearly below expected). The MoCA should be used preferentially for mild cognitive change screening.