[The "obsessive-compulsive spectrum": a useful concept?].

There is a second wave of research following the interest in Obsessive Compulsive Disorder (OCD) that explores a vast number of other conditions with some superficial similarity to OCD. These have in common an inability to delay or inhibit repetitive behaviors. While some interesting pharmacological treatment trials have emerged, few of the studies have truly explored the idea of a spectrum from the neurobiological point of view. Only for Tourette's Disorder, Trichotillomania and possibly Sydenham's Chorea have there been convincing biological evidence for continuity with OCD.