Navigating the diagnostic challenges of maladaptive daydreaming: a case report of ego-syntonic and ego-dystonic obsessive fantasies with functional impairment in a 17-year-old

Introduction Maladaptive daydreaming (MD) is an emerging and insufficiently recognized clinical phenomenon characterized by immersive fantasy activity associated with functional impairment. Its overlap with obsessive–compulsive disorder (OCD), autism spectrum disorder (ASD), and schizophrenia spectrum conditions creates significant diagnostic uncertainty, particularly in adolescents. Case presentation We report the case of a 17-year-old female presenting with intrusive celebrity-focused fantasies, sleep disturbance, behavioral regression, social withdrawal, and reduced self-care. She described co-existing ego-syntonic and ego-dystonic obsessive imagery with auditory-like pseudo-hallucinatory experiences. The Maladaptive Daydreaming Scale (MDS-16) score was 76%, consistent with probable MD. Extensive medical and neuroimaging investigations were unremarkable. Differential diagnoses included OCD, schizotypal traits, ASD, and schizophrenia prodrome. Intervention and outcome Initial treatment with fluoxetine was changed to quetiapine, alongside cognitive behavioral therapy, occupational therapy, structured behavioral strategies, and family psychoeducation. The patient demonstrated gradual improvement in distress, insight, sleep, and engagement, although intrusive fantasies persisted. Conclusion This case highlights the complexity of distinguishing MD from other psychiatric conditions in adolescents and supports the value of a multidisciplinary, function-focused management approach. Early recognition may prevent misdiagnosis and inappropriate treatment. Number of clinical trials Not applicable.