Obsessive-compulsive disorder: A disorder of pessimal (non-functional) motor behavior

R. Zor, H. Keren, H. Hermesh, H. Szechtman, J. Mort, D. Eilam*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Objective: To determine whether in addition to repetitiveness, the motor rituals of patients with obsessive-compulsive disorder (OCD) involve reduced functionality due to numerous and measurable acts that are irrelevant and unnecessary for task completion. Method: Comparing motor rituals of OCD patients with behavior of non-patient control individuals who were instructed to perform the same motor task. Results: Obsessive-compulsive disorder behavior comprises abundant acts that were not performed by the controls. These acts seem unnecessary or even irrelevant for the task that the patients were performing, and therefore are termed 'non-functional'. Non-functional acts comprise some 60% of OCD motor behavior. Moreover, OCD behavior consists of short chains of functional acts bounded by long chains of non-functional acts. Conclusion: The abundance of irrelevant or unnecessary acts in OCD motor rituals represents reduced functionality in terms of task completion, typifying OCD rituals as pessimal behavior (antonym of optimal behavior).

Original languageEnglish
Pages (from-to)288-298
Number of pages11
JournalActa Psychiatrica Scandinavica
Issue number4
StatePublished - Oct 2009


  • Compulsive content
  • Compulsive ritual
  • Functional impairment
  • Ritualization
  • Sequential order
  • Temporal order


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