Obsessive Compulsive disorder
Depression
Post Traumatic Stress Disorder (PTSD)
split personality disorder
No. This is a mental disorder and animals do not operate on a sufficiently high enough level cognitively or intellectually to be plagued with such. EDIT: GID is not a mental disorder.
obsessive-compulsive disorder
Arrogance and you don't have to be a mental patient to suffer from it.
Depression is not only a common mental disorder, but one of the single most common. Somewhere around one in five men suffer from depression, and one in three women.
Not all mental abusers are. A narcissist is someone who suffers from a specific personality disorder called "Narcissistic Personality Disorder." This disorder is relatively rare. Not all abusers suffer from the Narcissistic Personality Disorder (NPD) - although many of them have narcissistic traits.
Some sort of mental disorder. At the time they called all such complaints schizophrenia.
I would say Spongebob has an extreme case of autism.
If I understand the question, then you would be able to work if you suffered from Borderline Personality Disorder. The Mental Health Act 2007 ensures that people who suffer from mental illness have equal rights with regards to employment.