Compulsivity and free will.

‘‘The perfection of a science is shown in the perfection of its language,’’ Condillac said in 1746. A concept that is gaining in popularity and cropping up in scientific articles with increasing regularity is ‘‘compulsivity.’’ Off the cuff, the word ‘‘compulsive’’ makes us think of something that is controlled, repeated, inexorable, repetitive, imperative, stereotyped, and necessary—something you ‘‘have to’’ do. Compulsivity is associated with addiction, obsessive–compulsive disorder, paraphilia, obesity, anorexia, bulimia, hoarding, pathological buying and gambling, kleptomania, body dysmorphic disorder, trichotillomania, etc. But what is compulsivity? Nobody knows exactly. Though the word is often used, no one has ever come up with a clear definition. And yet ‘‘compulsivity’’ is more than just another new word. Funds have been made available to research it, researchers have applied for this funding, patients have been interviewed, control subjects have been approached, PhD projects have been launched, scales have been designed, papers have been written and rejected, symposia have been set up, lectures have been cancelled, tests have been designed, people have been placed under scanners, and extensive research has been carried out on animals. People have deliberated, assessed, and drawn conclusions, and money has been allocated and withdrawn about a word that has not even been defined. Condillac’s opinion about psychiatry would be firm. What is compulsivity? Can we learn something from the different scientific contexts in which compulsivity occurs? With addiction, compulsivity is understood as the final stage of a process of positive reinforcement that results in a habit from which the individual can no longer escape: Once caught in the compulsive trap, there is no natural way to go back. With compulsive disorder, the emphasis lies on the subjective experience of loss of control. The word subjective is important here because there is no true loss of control, just a feeling of loss of control. Being compelled to think or do something is explicitly experienced as pathological. It is an interesting paradox that patients with compulsive disorder bring about precisely what they are seeking to prevent— performing compulsions for fear of loss of control, which themselves result in a loss of control. With tics, compulsivity is closer to the idea of a motoric, prereflective component that precedes explicit awareness. Tics are a peculiar hybrid of a voluntary and an involuntary act. With trichotillomania, the emphasis is on the urge—the uncontrollable, impulsive aspect. Performing the act may indeed be compulsive, but it is also satisfying. This disorder confronts us with the difficult distinction between impulsivity and compulsivity. In obsessive–compulsive personality disorder, compulsivity seems to be associated with a personalitylinked, imperative engagement with the world, a form of rigidity with no functional meaning and usually with a total lack of insight on the part of the patient. In normal bedtime rituals of children, compulsivity manifests itself in the compelling force of ceremonial rituals that clearly function as an ordering principle for their awakening world. The fact that compulsivity does not exclusively belong to the field of pathology is clearly demonstrated by the countless, sometimes bizarre, rituals performed by athletes. Again, these have a functional significance that is linked to performance. And last, compulsivity is not an exclusively human trait but manifests itself in different ways among different species of animals, with the repetitive element being the most salient. There is no denying that compulsivity in psychiatry currently has several meanings, though the common use of a single term constantly creates a certain illusion of unambiguity. There are two obvious questions to ask. Firstly, are there different ‘‘compulsivities’’ that we incorrectly label with a single term? Should we in fact be referring to compulsivity type 1, type 2, type 3, etc? Or is there a single type of compulsivity that manifests itself in different variants? With the first question, we must then ask ourselves what the distinguishing features are of the different types, and in the second, *Address for correspondence: Prof. Dr. Damiaan Denys, AMC–Department of Psychiatry, PA.2-179, PO Box: 75867, 1070 AW Amsterdam, Netherlands. (Email: [email protected])