Does the divorce of a person afflicted with obsessive-compulsive disorder take effect if he utters it internally, or is that from the whisperings of Satan?

Divorce due to obsessive doubts does not take effect, nor does divorce take effect through inner thoughts without uttering them. If you doubt whether you uttered the divorce or whether the divorce was by your choice or due to obsessive doubts, then the divorce does not take effect, because the default state is the continuation of the marriage. Therefore, turn away from these obsessive doubts and seek help from Allah.