Here's the American Psychological Association talking. Here's something that they say:
"They may not only experience an inner sense of not belonging but also discrimination, harassment, sometimes lethal violence and denial of basic human rights. These issues, too, often bring transgender people into contact with mental health professionals."
And here's the link.
http://www.apa.org/pi/lgbt/programs/transgender/
Of course by calling them "it" you are contesting whether or not they are even human so you are a threat to their human rights.
Of course they can have other psychological problems because just by being in a gender conflict like they are that can cause psychological issues, But a lot of their psychological problems stem from the prejudices of people like you and occulus.