The self-mutilative nature of severe onychophagia: a comparison with self-cutting.

OBJECTIVE

To investigate the psychophysiological pattern associated with severe and mild onychophagia, and to compare this pattern with that demonstrated by previous research on self-cutting.

METHOD

Comparisons between the psychophysiological responses accompanying 3 behaviours were made using a guided imagery methodology. Imagery of nail-related, skin-cutting, and neutral events were presented in 4 stages.

RESULTS

Experiment I distinguished participants exhibiting severe and mild onychophagia by the severity and frequency of nail-biting and by the pattern of psychophysiological response across the stages. Experiment II indicated that the change in psychophysiological arousal accompanying severe onychophagia was not as dramatic as that demonstrated for skin-cutting. The behaviour seems to be less effective in reducing tension.

CONCLUSION

Severe onychophagia appears to manage the level of tension experienced by an individual, instead of dramatically reducing it in times of crisis. Such a process is consistent with that demonstrated in individuals with obsessive-compulsive disorder.