Diagnostic Overlap between Dissociative Disorders and Autoimmune Encephalitis in Adolescent Girls: A Case Series

Dissociative symptoms are common in primary psychiatric illnesses like depressive disorders, anxiety disorders and stress-related disorders and less common in organic conditions like seizure disorder and autoimmune encephalitis. Distinguishing between psychiatric and organic origins of dissociative symptoms often presents a significant diagnostic burden, especially in cases of autoimmune encephalitis, which is more commonly seen in adolescent females. Its close resemblance to dissociative presentations frequently delays diagnosis and treatment, which adversely impacts the prognosis. We present a case series of three adolescent girls, aged 15 to 17 years, who presented with dissociative symptoms and were evaluated at a tertiary care centre in rural Kerala, India. Case one presented with confirmed, seropositive anti-N-Methyl-D-Aspartate Receptor (NMDAR) encephalitis; case two with probable anti-NMDAR encephalitis with a concurrent ovarian teratoma confirmed on histopathology; and case three with a dissociative disorder in the context of adjustment difficulties. Management of cases involved immunotherapy, surgery, psychosocial intervention and antidepressant medication depending on the aetiology of the case. This case series emphasises the necessity of having a high index of suspicion for autoimmune encephalitis when an adolescent girl presents with dissociative symptoms and to avoid a psychiatric misdiagnosis.