Operant learning (R-S) principles applied to nail-biting

Association of nail biting and psychiatric disorders in children and their parents in a psychiatrically referred sample of children

BACKGROUND

Nail biting (NB) is a very common unwanted behavior. The majority of children are motivated to stop NB and have already tried to stop it, but are generally unsuccessful in doing so. It is a difficult behavior to modify or treat. The objective of this study was to investigate the prevalence of co-morbid psychiatric disorders in a clinical sample of children with NB who present at a child and adolescent mental healthcare outpatient clinic and the prevalence of psychiatric disorders in their parents.

METHOD

A consecutive sample of 450 referred children was examined for NB and 63 (14%) were found to have NB. The children and adolescents with nail biting and their parents were interviewed according to DSM-IV diagnostic criteria. They were also asked about lip biting, head banging, skin biting, and hair pulling behaviors.

RESULTS

Nail biting is common amongst children and adolescents referred to a child and adolescent mental health clinic. The most common co-morbid psychiatric disorders in these children were attention deficit hyperactivity disorder (74.6%), oppositional defiant disorder (36%), separation anxiety disorder (20.6%), enuresis (15.6%), tic disorder (12.7%) and obsessive compulsive disorder (11.1%). The rates of major depressive disorder, mental retardation, and pervasive developmental disorder were 6.7%, 9.5%, 3.2%, respectively. There was no association between the age of onset of nail biting and the co-morbid psychiatric disorder. Severity and frequency of NB were not associated with any co-morbid psychiatric disorder. About 56.8% of the mothers and 45.9% of the fathers were suffering from at least one psychiatric disorder. The most common psychiatric disorder found in these parents was major depression.

CONCLUSION

Nail biting presents in a significant proportion of referrals to a mental healthcare clinic setting. Nail biting should be routinely looked for and asked for in the child and adolescent mental healthcare setting because it is common in a clinical population, easily visible in consultation and relatively unintrusive to ask about. If present, its detection can then be followed by looking for other more subtle stereotypic or self-mutilating behaviors.

What is the function of nail biting: an analog assessment study

OBJECTIVE

To compare the frequency of nail biting in 4 settings (interventions) designed to elicit the functions of nail biting and to compare the results with a self-report questionnaire about the functions of nail biting.

DESIGN

Randomised allocation of participants to order of conditions.

SETTING

University Psychology Department.

SUBJECTS

Forty undergraduates who reported biting their nails.

INTERVENTIONS

Left alone (boredom), solving maths problems (frustration), reprimanded for nail biting (contingent attention), continuous conversation (noncontingent attention).

MAIN OUTCOME MEASURES

Number of times the undergraduates bit their nails.

RESULTS

Nail biting occurred most often in two conditions, boredom and frustration.

CONCLUSION

Nail biting in young adults occurs as a result of boredom or working on difficult problems, which may reflect a particular emotional state. It occurs least often when people are engaged in social interaction or when they are reprimanded for the behavior.

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.

Severe morbid onychophagia: the classification as self-mutilation and a proposed model of maintenance

OBJECTIVES

The aim of this review is to make a distinction between a mild and a severe form of onychophagia (nailbiting) that has not been adequately recognised in clinical research. Furthermore, the aim is to emphasise the need for greater understanding of the motivation for such self-injury as occurs in the severe form. The purpose of making the distinction is to evaluate whether a label of self-mutilation can be applied to the severe form. If this is the case, the tension-reduction model of self-mutilation can be proposed as the mechanism which may maintain the behaviour in the face of serious social and physical consequences.

METHOD

Examination was made of the literature relating to onychophagia and to self-mutilation. Treatment studies of onychophagia were examined to evaluate the mechanisms by which the behaviour may be maintained.

RESULTS

Considering the self-mutilative nature of the severe form and the common theme of tension reduction in the literature on onychophagia, application of the tension-reduction model of self-mutilation is warranted.

CONCLUSION

There is a need for empirical research as to the tension-reducing nature of severe onychophagia.