Psychology Article Review Paper on Habit Reversal Techniques in Controlling Nail Biting

Habit Reversal Techniques in Controlling Nail Biting


The treatment of Nail biting has received minimal attention. So far therapeutic measures against it have not been significant. The review provides an analytic view of the disorder with an aim of addressing its control measures based on habit reversal mechanism. Comparative article review methodology has been adopted. Knowledge gap identified herein would be necessary for further studies that would enable effective clinical therapeutic measures on co-morbid disorder.

Key words: Nail biting, co-morbid disorder, therapeutic measures, review


Nail biting has received minimal attention and therapeutic measures against it have not been significant. This has caused affected families to accept it though, with impartiality as several treatment attempts have not been successful (Nunn & Azrin, 1976).


Nail biting (also called onychophagia) is an unwanted psychological practice common in young children and adolescents. In most cases, children are usually warned against the behavior but due to its complexity to modification, it ends up with individuals even during adolescent stages and adulthood (Nunn & Azrin 1976; Ahmad, 2008).

Studies by Nunn and Azrin (1976) indicate that about 43 % of school boys and girls respectively suffer from this psychological disorder. However, this study has not provided the reason for this behavior among children. Quite a number of etiological factors lead to nail biting habits. These are individual’s inactivity, loneliness, stress and anxiety (Ahmad et al, 2013). Adult or adolescent nail biting can be as a result of boredom and depression (Ahmad &Shekoohi, 2011). In psychiatric disorders like tic disorder, nail biting is a co-morbid challenge. This is highly enhanced by parental genetic transfer as many children with psychiatric disorder have parents with historical psychiatric experience (Ahmad &Shekoohi, 2011; Nunn & Azrin 1976).

According to (Ahmad, 2008), several factors contribute to nail biting behavior. About 70% of nail biting cases are as a result of lack of attention. About 36 % were due to opposition factor while 20 % were due to seclusion. Moreover, approximately 15% are due to enuresis, 13 % tic disorder and about 11% from compulsive oriented factors. This study goes further to provide statistical facts on depressive, mental pervasiveness and mental retardation disorders. These have percentage values of 6.7, 9.5 and 3.2 respectively (Ahmad, 2008). However, the limitation encountered in the study is the establishment of the relationship between nail biting on on-set age and co-morbid psychiatric disorder. Although the frequency of nail biting cases were not associated with co-morbid psychiatric disorders, this study agrees with (Ahmad &Shekoohi, 2011)  ) on the parental gene transfer effects to children psychiatric disorders, showing that specific mental disorders affecting about 57 %  of parental psychiatric disorders are depression oriented. 

However, the results by (Ahmad, 2008) provide a general trend of the disorder for both genders. This trend is also observed in (Nunn & Azrin 1976) where statistical results are provided for one gender (boys) in comparison to the other, although, in this study, factors contributing to the disorder are the same as the ones by (Ahmad, 2008) and (Ahmad &Shekoohi, 2011).

Other study reports an average of 27 % psychiatric cases among school age teen girls but lacks statistical data on boys within the same age bracket (Ahmad &Shekoohi, 2011). However, additional information on the disorder prevalence among boys in adolescence than girls (at the same age bracket) is mentioned.  Different from other studies, this study narrows down to relationship between gender and co-morbid psychiatry at school going children below ten years and reports a lack of dependability of nail biting on gender (Ahmad &Shekoohi, 2011). Also, it observed that dependability of the psychiatric disorders on onset age, rate of nail biting and physical body injury is minimal ((Ahmad &Shekoohi, 2011).  From the observations in this study and the other studies, it is evident that co-morbid disorder is a factor of gender but during or after adolescence. Therefore, what causes a link between gender and co-morbid disorder only after adolescence but not at early ages?

On the effects of nail biting, the study by Ahmad and Shekoohi (2010) indicates that several complications such as teeth root resorption, anterior teeth malocclusion, intestinal parasitic infections, bacterial infections, alteration of the oral carriage of enterobacteriaceae besides destruction of alveolar can result. Although the study reports possibility of relational dependence of temporo-mandibular joint infections to nail biting, concrete data to support this claim is not provided.

The effect of nail biting among children can lead to destruction of the nail bed, giardia infections and un-functionality of the temporo-mandibular (Ahmad &Shekoohi, 2011). From this study, common control action is punishment from parents ((Ahmad &Shekoohi, 2011).

Though nail biting is a prevalent case among family members, it has not received significant medical solution thereby following individuals from young age through the entire growth and development period (Nunn & Nazrin, 1976))

Any of the two methods available can be used for controlling chronic nail biting among children and adolescents. These are Habit Rehearsal Training (HRT) and Object manipulation training (OMT) (Ahmad &Shekoohi, 2011); Nunn & Azrin, 1976). Generally, the former has been found to be more effective than the latter technique. (Ahmad &Shekoohi, 2011). Habit Reversal techniques demands active parental involvement. However, a limitation is foreseen especially in cases where parental mental health is co-morbid ((Ahmad &Shekoohi, 2011).

Behavior therapy for treatment of nail biting includes wearing a protective permanent wristband, aversion method, self-help technique and progressive muscle relaxation methods. Most of these methods have been found to decrease frequencies in nail biting in different degrees. For instance, wristband method decrease highly decreases nail; biting as compared to aversion method although, the latter is more effective than the former (Ahmad &Shekoohi, 2011).

The work presented in this review form part of the studies on habit reversal approaches to nail biting. Knowledge gap identified herein provides a leeway for further studies on this subject that would enable effective clinical therapeutic measures on nail biting.


Ahmad Ghanizadeh (2008). Association of Nail Biting and Psychiatric Disoders in Children and their Parents in a Psychiatric Refered Sample of Children. Children Adolescents Psychiatry Mental Health. 2008; 2: 13. Published online 2008 June 2. doi: 10.1186/1753-2000-2-13PMCID: PMC2435519. Web. Retrieved from

Ahmad Ghanizadeh, Hajar Shekoohi (2011). Prevalence of Nail Biting and its Association with Mental Health in a Community Sample of Children. BMC Res Notes. 2011; 4: 116. Published online 2011 April 11. doi: 10.1186/1756-0500-4-116.  PMCID: PMC3082216Web. Retrieved from

Nunn R. and Azrin N (1976).  Eliminating nail-biting by the habit reversal procedure. Southern Illinois University USA Behavior Research and Therapy (Impact Factor: 3.3). 02/1976; 14(1):65-7. DOI: 10.1016/0005-7967(76)90046-2 .Retrieved from