Facial expressions are inherently linked to emotions and are a visual tool to communicate emotions to the surrounding world. A number of studies have evaluated the aptitude of different portions of the population in recognizing specific facial expressions. It is known that certain differences in the ability to correctly identify or assess the intensity of a facial expression can be attributed to psychological disorders. In particular, specific disorders seem to affect the processing of a particular emotion and the perception and interpretation of its associated facial expression. This work aims to summarize existing findings in literature on the topic and provide an outlook for potential technological use-cases, which can be applicable in the field of psychotherapy.