Abstract
In this case report we present a 27 year old male patient diagnosed finally as simple schizophrenia who had an earlier diagnosis of frontotemporal dementia and frontotemporal syndrome. This case ilustrates difficulties in differential diagnosis of a group of diseases like schizophrenia, frontotemporal dementia and autism, in which dysfunction of prefrontal cortex is a common feature. These disorders usually manifest with apathy, anhedonia, social withdrawal, lack of insight, mental rigidity and inflexibility insidious onset and gradual progression. Treatment with aripiprazole led to significant amelioration of negative symptoms and improvement of social functioning.