Organic and neurodegenerative mimics of very late-life obsessive–compulsive disorder: A diagnostic challenge

ABSTRACT Very late-onset obsessive-compulsive symptoms, defined as onset after 60 years of age, are uncommon and often pose a diagnostic challenge. In older adults, such behaviors may mimic primary obsessive-compulsive disorder (OCD) but can arise secondary to neurodegenerative, metabolic, endocrine, or iatrogenic factors. Misdiagnosis can lead to inappropriate treatment and poor outcomes. This case series highlights the diverse etiologies that can present with late-life OCD-like behaviors, including nutritional deficiencies, behavioral variant frontotemporal dementia, endocrine disturbances such as syndrome of inappropriate antidiuretic hormone secretion (SIADH), and dopaminergic therapy-induced punding in Parkinson’s disease. Differentiating features include the temporal onset of symptoms, presence or absence of anxiety-driven obsessions, insight, cognitive status, laboratory and neuroimaging findings, and medication history. Recognizing these underlying conditions is essential, as effective treatment typically requires a multidisciplinary approach that combines thorough history-taking and targeted diagnostic investigations to ensure accurate diagnosis and optimize management outcome.