How to stop biting nails: rub your fingertips

Study finds gentle replacement methods can reduce unwanted habits, including pulling hair and picking skin

Biting nails can be tied to stress. Photo: Yuri Arcurs

For those who can’t stop biting their nails, pulling their hair or picking their skin there might be a simple solution, a new study suggests.

Research recently published in the medical journal Jama Dermatology found an approach called habit replacement may help reduce repetitive behaviour.

A six-week study of 268 participants was aimed at easing body-focused repetitive behaviours such as nail biting, skin picking or hair pulling – conditions that are sometimes tied to stress. The participants were split into two random groups. One group was tasked with habit replacement, while participants in the other were told they were waitlisted for treatment. The latter group was trained on the method at the end of the study.

Those in the first group who learned about the technique were given a manual and video that showed them how to do it by gently rubbing their fingertips, palm or arm any time they felt the urge to bite their nails or engage in harmful behaviour. They were also instructed to practice the new habit when they weren’t feeling the urge to pull, pick or bite.

The strategy helped 53 per cent of the participants cut back on the unwanted habits. Around 80 per cent said they were satisfied with the training for the self-help intervention, while 86 per cent would recommend the treatment to others.

“The rule is just to touch your body lightly,” lead study author Steffen Moritz, of Germany's University Medical Centre Hamburg-Eppendorf, told NBC News. “If you’re under stress, you might perform the movements faster, but not with more self-applied pressure.”

It was suggested that more research is needed but the hope is can join other tried-and-tested methods for body-focused repetitive behaviours, such as decoupling and habit reversal training.

Decoupling involves starting a habit but switching it at the last minute, such as those who feel the urge to bite their nails. For example, as nail biters bring their hands to their mouths, they're instead taught to touch their earlobe.

Habit reversal therapy, meanwhile, is a training that helps people reverse or unlearn a bad habit. For example, any time an urge comes to pick at their skin, they're taught to clench their fist or sit on their hands instead.

More information needed

The study concluded habit replacement "is a feasible and effective self-help strategy" against repetitive behaviours, especially for nail biting, but that it is missing follow-up data despite showing promise.

There are also some limitations on the study including the relatively short amount of time at only six weeks and its lack of diversity since most of the participants were white women in their 30s who did not have their diagnoses confirmed. It also isn't clear if the intervention was affected by other conditions such as anxiety or depression or helped reduce impairment.

However, John Piacentini, of TLC Foundation for Body-Focused Repetitive Behaviors, told NBC News it was a step in the right direction. These conditions are believed to affect about 5 per cent of people globally.

"It is fantastic that this study will raise awareness of BFRBs because they’re really poorly understood, oftentimes misdiagnosed or missed completely," Piacentini said.

“There are reasonably good treatments out there that most clinicians aren’t aware of or don’t do."