Case Report: Subacute combined degeneration misdiagnosed as a primary affective disorder: diagnostic pitfalls and clinical red flags

BackgroundSubacute combined degeneration (SCD) of the spinal cord is a progressive neurological disorder caused by vitamin B12 deficiency. When initial symptoms present as nonspecific fatigue, dizziness, and affective distress, the condition is frequently misattributed to primary psychiatric disorders. This “diagnostic overshadowing” leads to critical delays in administering definitive therapy, risking irreversible axonal damage.Case presentationA 39-year-old male presented with a nine-month his