Pica and the obsessive-compulsive spectrum disorders.

BACKGROUND: The concept of a spectrum of obsessive-compulsive related disorders may have clinical and research heuristic value in the approach to disorders similar to obsessive-compulsive disorder (OCD) in respect of phenomenology and psychobiology. Like other repetitive and ritualistic behaviours, pica may be postulated to fall at times on this spectrum.

METHODS: Five cases of pica seen at our clinics are presented here in order to test this hypothesis. Phenomenology, neurobiology (where available) and pharmacotherapy data are provided in order to consider a possible relationship with OCD and OCD spectrum disorders.

RESULTS: In 2 of the cases, pica appeared to be a compulsion and patients had additional symptoms which met diagnostic criteria for OCD. In 2 of the cases, the clinical picture and neurobiological data were reminiscent of an impulse control disorder. Four of the 5 patients responded to treatment with a serotonin re-uptake inhibitor (SRI).

CONCLUSION: These results are consistent with a hypothesis that at least some cases of pica may usefully be conceptualised as lying within a compulsive-impulsive spectrum of symptoms and disorders.