A 24-year-old woman describes stopping mid-conversation multiple times a day, each time completely losing the thread of what she was saying, with no recollection afterward of her original point. She denies any sense that someone or something is removing her thoughts — she says it 'just goes blank.' Before revealing the answer: what is the finding here, and what detail in her account would make you suspicious this was thought withdrawal instead?
This is thought blocking. The key differentiator from thought withdrawal is the absence of any delusional attribution: she experiences a gap, not an act done to her. If she instead described her thoughts being 'taken out of her head' by someone or something outside herself, with the same degree of conviction as any other delusion, that would point to thought withdrawal rather than thought blocking.
References
- Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 4, 'Disorders of Thought and Speech'.