Final answer:
The characteristic difficulty in perceiving facial emotions and understanding others' mental states is associated with Autism Spectrum Disorder (ASD), rather than the other listed mental health conditions.
Step-by-step explanation:
Difficulty perceiving facial emotions and reading others' states of mind is characteristic of Autism Spectrum Disorder (ASD), not schizophrenia, anorexia nervosa, obsessive-compulsive disorder, or attention-deficit hyperactivity disorder. In the context of the provided question, the most fitting answer is autism spectrum disorder, as it includes symptoms of impaired social skills, such as difficulty making and maintaining eye contact, reading social cues, and feeling empathy for others. Schizophrenia, while it does affect social interactions and emotion perception, is more associated with symptoms like hallucinations, delusions, and issues distinguishing reality from imagination.