Psychosis
A mental condition whereby the patient completely loses touch with reality.
Psychosis versus Neurosis
The term 'psychosis' denotes an severe form of mental illness, while 'neurosis' denotes less severe forms.
Sigmund Freud elaborated a distinction between psychosis and neurosis.[1]
"[In] neurosis the ego suppresses part of the id out of allegiance to reality, whereas in psychosis it lets itself be carried away by the id and detached from a part of reality."[2]
Psychosis and Lacan
Jacques Lacan studied psychosis for his doctoral research about a woman he calls "Aimee."[3]
It is common to compare Lacan's style of writing and speaking to the discourse of psychotic patients.
Psychosis has many different forms: paranoia, schizophrenia, and manic-depression.[4]