Change in the experience of oneself may lay the groundwork for the development of additional hallucinations and delusions in individuals with schizophrenia. However, to date, the course and symptom and functioning correlates of passivity symptoms (cf. thought insertion, thought withdrawal) have not been measured consistently over long periods of time. Information on the course and correlates of passivity symptoms is essential for developing models of their contribution to schizophrenic illness.

Eighty-two individuals diagnosed with schizophrenia or schizoaffective disorder were recruited at an index hospitalization and reassessed at three or more follow-ups over the following 18 years.

The results indicate that a small group of participants report passivity symptoms at all follow-ups, many reported passivity symptoms at some follow-ups, and the majority of individuals never reported passivity symptoms. The prevalence of passivity symptoms was similar to that for delusions of reference and persecutory delusions. Notably, when individuals did experience passivity symptoms, they also had a greater number of additional psychotic symptoms than individuals without passivity symptoms. Further, the presence of passivity symptoms was associated with work impairment at some assessments.

Passivity symptoms present episodically, at a similar rate as delusions of reference and persecutory delusions, and when present, they are associated with having a higher number of additional psychotic symptoms, as well as having some impact on work functioning. These results suggest that passivity symptoms may increase vulnerability to additional psychotic symptoms and greater work impairment.