Is there any scientific evidence or proof of why people bite their nails?

Question

What or where would it be please?

Answer 1

Steven is onto the right track. Nail biting does have a psychological basis. More specifically, nail biting is a manifestation of obsessive compulsive disorder. Compulsive nail biters will chew on their nails in response to stress or anxiety. In many cases, they will do so without being fully aware of their actions. There have been a number of papers published on the topic (see references below). You might be able to track some of them down on the internet.

Answer 2

I'm pretty sure it's psychological.

When people develop habits like this, it starts to become a subconscious action, and often times they do not realize they are doing it so much. I don't have anything specific to show you, but I know it is just based on the patterns of human brain function.

Answer 3

Yes.

Answer 4

I believe it's just a bad habit.

Answer 5

Although this has always been limited to discussing matters related to trichotillomania, I would like to introduce a slightly different but related topic. It may come as no surprise that there are other types of problem behaviors quite similar to trich in a number of ways. I am referring specifically to compulsive skin picking and nail biting (also known as onychophagia). These may not sound serious, but neither does hair pulling to some people. Since I have met quite a number of people who have one of these problems in addition to trich, I now routinely screen for them.


What I am referring to is not the kind of little bits of rough nail or cuticle that everyone picks at or bites from time to time, nor is it the occasional blemish that people might squeeze or pick. These nail-biters continually bite their nails past the nail bed and their cuticles until they bleed and are constantly walking around with red, sore, and sometimes infected fingers. Those who pick their skin compulsively have their faces and bodies covered, at times, with red sores and scabs known as acne excoria, a self-inflicted skin disorder that resembles acne. The smallest pimple or blemish must be opened and picked at or squeezed, either with the fingers or another implement such as tweezers, needles, pins, toothpicks, etc. Numerous scars are often the result.


Just as those with trich wear hats, scarves, wigs and makeup, nail-biters keep their hands behind their backs or in their pockets, and skin pickers wear makeup, put on clothing that covers bad areas, apply Band-Aids or just stay indoors when looking their worst. They feel the same shame and social embarrassment and experience that out-of-control feelings at times. They, too, wonder why they can't stop and they also question whether or not they are crazy.


Another similarity between these problems and trichotillomania is that they seem to happen when people are in one of two modes. Some do it in an automatic way, as if they are in a trance and not really thinking about what they are doing. Usually, they are involved in some other activity at the same time such as reading, talking on the phone, working at the computer, watching TV, etc. For others, the deliberate picking or biting is their main activity at the time, and they will frequently interrupt other activities to engage in it.


There is also a strong commonality seen in the various purposes behind these three problems. At the most basic level, they satisfy an urge. Many report an almost uncontrollable feeling of needing to do them. Pulling, picking or biting also seem to deliver a pleasurable or relaxed sensation. When sufferers feel stressed, doing these things has a kind of soothing effect on their nervous systems, and reduces levels of stimulation. On the other hand, when they are bored or inactive, they seems to provide a needed level of stimulation to the nervous system. This probably accounts for why so many people who dislike doing them find it so hard to stop. It simply "feels good" at the time, no matter what the consequences. These behaviors may really be all about self-regulation in certain individuals whose nervous system may not be doing a very good job of regulating itself (see the article "A Sensory Regulation Theory of Trichotillomania," on this website).


Another factor also seems to be at work for a subgroup of people. This involves a kind of compulsive perfectionism. Some hair-pullers must pull "special" hairs that feel "different" or as if they don't belong due to their look or feel. In the same way, nail-biters will often try to bite off rough-feeling or broken bits of cuticle or nail sticking out in order to make their nails feel smooth and look "perfect" or regular. Skin-pickers will stand for hours in front of mirrors closely examining their faces or other body areas for the tiniest bump, irregularity or enlarged pore and then try to eliminate it, or drain it, in hopes of achieving a 'perfectly' clear complexion. Paradoxically, all of those who pursue such goals always end up looking much worse in spite of their efforts, as a result of the damage that they do to themselves.


What all these similarities seem to point to is that these three behaviors are probably all different aspects of the same problem.Some have theorized that theret may be that the same out-of-control grooming mechanism in the brain underlies them all. My own theory is that there may be some type of dysfunction of a brain mechanism that regulates levels of stimulation within the central nervous system, and that these behaviors represent an attempt to control these internal stimulation levels externally. People seem to pull, pick, or bite when thery are either overstimulated (dus to stress or excitement) or understimulated (due to boredom or inactivity). Many similar behaviors can be observed in animals who are kept in confined or unstimulating environments, or who live in stressful conditions.

There are many that now believe that compulsive hair pulling, skin picking, and nail biting form a subgroup of what is becoming known as the Obsessive- Compulsive Disorder Spectrum. OCD has been previously been regarded as only a single disorder. It may in fact represent a range of related disorders, including classic OCD, Body Dysmorphic Disorder, Anorexia Nervosa, Bulimia, Trichotillomania, Onychophagia, Compulsive Skin Picking, Compulsive Nail Biting, and Tourette's Syndrome. Recently, a new term has been coined for these problems - Body-focused Repetitive Behaviors (BFRBs). As with trichotillomania, skin picking and nail biting are considered to originate within the chemistry of the brain, and may well have an underlying genetic cause.


In my own practice, I have seen quite a few hair pullers who also bite their nails and/or pick at their skin. While it has never been surveyed systematically, there may be many out there with multiple symptoms. Interestingly, quite a number of people don't realize that their several problems may be connected until it is pointed out.


As with trich, these other two disorders appear to respond best to medication and behavioral therapy. Medication should never be considered an end in itself, but a tool to help you do the therapy. Drugs which remedy these problems do not work instantly- It may take several weeks before you see any results. They also may not work perfectly. Usually, 60-70% improvement from a medication is considered a good result. The medications mainly used to treat picking or biting problems are the same group as those used for Trich and OCD. This group is made up of the latest and most potent antidepressants, and includes Anafranil, Prozac, Zoloft, Paxil, Luvox, Celexa, Lexapro, Serzone and Effexor. Sometimes, these drugs may also be augmented with other medications, most often small amounts of the same medications used to treat schizophrenia. These would include Risperdal, Zyprexa, Seroquel, Geodon, and Abilify. Please note that this does not imply that people with BFRBs are in any way psychotic. Keep in mind that no one drug is best, since there is no drug works for everyone. You have to work your way through them in a trial-and-error way, until you find the one that is most effective for you. One further caution on medications is that they do not necessarily work for everyone.


One other option might be to try the B-vitamin inositol. I have seen this work in a number of cases. It seems to reduce the urge to pull or pick. It is broken down by the body into two secondary neurotransmitter chemicals that enhance the activity of serotonin in the brain. Serotonin, is a brain transmitter that may be implicated in OCD and related disorders. Inositol is usually taken in large quantities, but will not build up to toxic levels in your system, as it is a water soluble vitamin. Side effects can include gas and diarrhea, but usually, they will either quickly pass, or not occur at all. The vitamin is taken in powered form, and is built up to a maximum dosage of 18 grams over a six week period. Some people require the maximum, but some can get by with less. (You can get more detailed information about this in another article listed on this website. The title is "Inositol and Trichotillomania.") Inositol can also be safely used to augment antidepressant medication. The only exception is that it cannot be taken together with Lithium. Children generally take smaller doses than adults.


Therapy for these disorders consists of two parts. The first, is Habit Reversal Training (HRT), a four-step process which teaches you awareness of your habits, how to relax, how to breathe and center yourself, and to perform a competing and opposing muscle response. (I have described this technique in a previous issue of TLC's IN TOUCH, in an article on cognitive/behavioral therapy for trich, which I'm sure you can get copies of.) It can be extremely useful if practiced daily and stubbornly, as it must become as automatic as the habit you are aiming to eliminate. These are stubborn problems for two reasons. First, you have probably rehearsed the unwanted behaviors hundreds or even thousands of times. It is important to accept that they will not simply be overcome in a few days or weeks. Second, you are fighting the fact that they feel good to do, and provide much short range satisfaction and either stimulation or soothing. It takes time and a good deal of effort to master, but I believe it is worth it. Research shows it to be an effective technique.

The second part is known as Stimulus Control (SC). Skin picking and nail biting are a complex behaviors, with many different inputs. SC is a behavioral treatment that seeks to help sufferers first identify, and then eliminate, avoid, or change the particular activities, environmental factors, mood states, or circumstances that have become associated with, and that trigger picking or pulling. The goal here, is to consciously control these triggers that lead to the undesirable behaviors, and to create new learned connections between the urges new non-destructive behaviors. A much more in-depth description of these treatments can be found in my two books - "Obsessive-Compulsive Disorders: A Complete Guide to Getting Well and Staying Well," and "The Hair Pulling Problem: A Complete Guide to Trichotillomania." Both are published by the Oxford University Press, and you can find out more about them at www.ocdbook.com and www.trichbook.com ..


Even if you have more than one of these problems, don't despair. They can be overcome if you have the motivation. More important is learning to "de-stigmatize" yourself. You are not crazy, helpless, morally weak or totally out of control, even though you may feel like some or all of these things at times. Once you get down to realizing that you are just a person who simply happens to have a problem, you can start to make some serious progress. Skin picking and nail biting are chronic problems, so there currently isn't a 'cure', but you can find a recovery if you are willing to work at it