This final paper deals with Language and Mental Disorders. It contains the definition of neurolinguistics and psycholinguistics, explains the process of normal brain functioning and describes most important parts of the brain involved in the language processing. Furthermore, two most common phenomena have been explained and divided into categories. Apart from language disorders, some of the speech disorders have also been listed. Before introducing aphasia, its most common cause has been defined. In the chapter about aphasia, its syndromes were introduced, as well as some tips which could be helpful when talking to aphasic person. Autism spectrum disorder and its subcategories have been defined and provided with examples. Lastly, specific language impairment which occurs in childhood and Alzheimer’s disease which mostly occurs in adulthood have been briefly explained.