Your daughter has a condition known as trichotillomania, which is defined by some people as an impulse-control disorder and by others as a type of obsessive-compulsive disorder.

Although it's defined as a psychological problem, this doesn't mean your daughter automatically has a mental illness. Research has shown that, apart from their habit, people with trichotillomania have a healthy psyche, but it can be associated with depression, anxiety and other problems.

Trichotillomania is quite common - affecting at least 2 per cent of the population - and mostly starts around puberty or early adulthood. The person usually pulls out hair from the scalp or face (eyelashes or eyebrows) because it's easily accessible, but may pull out body hair, too.

Causes

The cause of trichotillomania isn't known. Most experts believe it's a type of obsessive-compulsive disorder, but there may be a hereditary element. Some blame environmental pollution, streptococcal infections, or even deficiencies of brain or body chemicals and nutrients.

I suspect the answer lies somewhere between pleasant habit and a reaction to stress, at least in terms of the initial trigger. People often start by pulling out damaged hairs to relieve an itch or a follicle, but as the habit progresses they may lose any reason for it.

Treatments

It's important to reassure your daughter there are treatments for trichotillomania, and she should talk to her GP.

Like other anxiety and compulsive problems, cognitive behavioural therapy (CBT) can be very effective. The two elements of this treatment are learning about the condition and what triggers it, and behavioural changes to avoid the hair-pulling, such as distraction strategies.

Drug treatments can also help, especially in combination with CBT and when associated problems such as depression are present. But drugs should be viewed as a temporary measure while the person gets on top of the problem. If drugs alone are used, the symptoms often return once they're stopped.

Some people have used hypnosis, biofeedback, diet and other strategies, so these may be worth trying.

This article was last medically reviewed by Dr Trisha Macnair in March 2008