There are lesser-known forms of OCD (usually referred to as Pure O) which manifests itself in the form of repetitive unwanted and disturbing thoughts that goes against what you believe is morally correct. (Also known as intrusive thoughts, different from hearing voices).
Many of these are unwanted sexual and violent thoughts. These are distressing and often leaves the sufferer feeling guilty, ashamed, saddened, disgusted or frightened (or a combination of those feelings).