Racing and crowded thoughts in mood disorders: A data-oriented theoretical reappraisal

Speed of thought is a central phenomenon in mood disorders. We aimed to provide an update on the topic ten years after a first narrative review published on racing and crowded thoughts in mood disorders. This update is based on recent publications, including recent works of our group.

Narrative review based on publications from the last ten years including publications of our group and a systematic research of references on PubMed.

The traditional dichotomist view of racing versus crowded thoughts is not refuted but appears to be more complex, as revealed by validation studies of the Racing and Crowded Thoughts Questionnaire. Moreover, this dualistic view can no longer be conceptualized in a simple bijective concordance with the distinction of hypomania versus mixed depression. We also show that racing/crowded thoughts are strongly associated with mixed depression and not with non-mixed depression, that they tend to be more associated in hypomania to irritability than to the typical symptoms of energy and activity increase and that they are clearly distinguishable from ruminations. Yet, although tightly linked to mood disorders, racing/crowded thoughts appear to be associated to anxiety as well as attention deficit/hyperactivity disorder and insomnia.

Racing and crowded thoughts should be studied in a dimensional perspective as an important facet of mind activity within and beyond the field of mood disorders.