Background and aims: Traumatic Brain Injuries (TBI) are lesions that cause permanent or temporary physical, cognitive and psychosocial disorders. Data shows that even single TBI have a long-term association with higher rates of neurodegenerative diseases as well as higher morbility and mortality rates. Objectives: We describe a Case Report of post TBI Dementia and the importance of its differential diagnosis as well as a recent literature review.Materials and Methods: Review of the patientu2019s records. A current literature review was performed after a Pubmedu00ae Database search with the following key-words: u201ctraumatic brain injuryu201d, u201cdementiau201d, u201cbipolar disorderu201d.Results: 60 year old male, no psychiatric history until 2016 when he was involved in a car crash that caused multiple facial fractures. After the accident, several behavioral changes were noticed, specifically poor performance in everyday tasks and adynamia.The patient was initially prescribed 300mg/day of bupropion (titrated) and after a few days developed symptoms of uninhibited sexual behavior, inappropriate clothing choices, irritability, decreased sleep and overactivity, for which he was committed in the psychiatry ward with the diagnosis of u201caltered behavior of unknown causeu201d.The patient was medicated with 1000mg/day Valproic Acid, 50mg/day Sertraline and 10mg/day olanzapine with marked improvement. In the post-discharge visit the patient presented with apathy, social isolation, cognitive deficit and sexual dysfunction u2013 at this point the possibility of Bipolar Disorder was considered.Conclusions: This case reports shows the paramount importance of differential diagnosis consideration and discussion - here we see an uncommon clinical presentation for Dementia - in these situations a wrong diagnosis may lead to sub-optimal treatments.