Alopecia areata is a skin disease which is characterised by the absence of hair in circular or oval areas, without scarring. It can affect the scalp of course, but also eyebrows, eyelashes or any other place on the body where there is hair. In adults, areas of baldness can also be seen in the beard or pubic area. The number and size of these areas of hair loss vary considerably from one individual to another, and can go as far as complete loss of hair over the entire body. This is known as "universal alopecia".
What causes alopecia areata?
Despite a great deal of research, the etiology of alopecia areata (etiology is the search for causes in medical terms) is far from certain.
However, medical research favours three families of possible causes. It suggests that alopecia areata may be triggered by genetic factors, immunological factors or even environmental factors.
- Genetic factors
Most cases of alopecia areata are sporadic, appearing and disappearing and then reappearing without anyone knowing exactly why.
Some studies have attempted to establish a correlation between the onset of the disease and the patient's family genetic make-up, in particular studies carried out on monozygotic twins.
These studies would suggest that there may be a weak correlation between alopecia areata and genetic factors : the prevalence of alopecia areata appears to be slightly higher among members of the same family, although the gene or genes responsible have not yet been identified.
- Immunological factors
Other research has attempted to establish a link between alopecia areata and other autoimmune diseases. For example, it was found that a patient with alopecia areata was twice as likely to develop vitiligo as another patient. In addition, people with vitiligo are 4 times more likely than other people to develop peladic skin disease.
Analyses have been carried out associating alopecia areata with other autoimmune diseases such as type 1 diabetes mellitus, rheumatoid arthritis and thyroid disease. But also asthma, psoriasis and atopic dermatitis.
The current hypothesis is that these autoimmune diseases generate the production of antibodies that affect the structure of hair follicles in the anagen phase. These antibodies (primarily T lymphocytes, but also natural killer cells such as macrophages, cytokines and Langerhans cells) are thought to cause inflammation around the hair follicles, followed by an alteration in the structure of the hair life cycle and, finally, a complete alteration in hair growth (apoptosis of the cells, i.e. their programmed death).
Note that at this stage, these hypotheses need to be confirmed, , the links between alopecia areata and autoimmune diseases remain statistically tenuous. - Environmental factors
Popular wisdom attributes the onset of alopecia areata to major stress.
Could the cause of alopecia areata be emotional?
Studies seem to confirm this insofar as one in four people suffering from alopecia areata report having experienced a traumatic event or major stress just before the onset of the disease.
Stress therefore appears to be the most common cause of the onset of alopecia areata although the cause-and-effect relationship has not yet been elucidated.
For the record, other possible triggers have been studied, such as infectious diseases or diet, as these factors can also be associated with a process of immune system deregulation. Today, none of these external factors is considered to be a serious factor in the onset of alopecia areata.
Who is affected by alopecia areata?
Various studies have established that alopecia areata affects between 1% and 2% of the population, with no real distinction between the sexes, although a slight predominance of women has been reported.
It has also been established that alopecia areata can affect almost any age group, with the greatest number of individuals affected between the ages of 10 and 25 and very few cases reported after the age of 60.
Does depression cause hair loss?
First and foremost, it's not always easy to recognise depression, which can manifest itself through different symptoms, both mental and physical, and each with different levels of severity.
Depression is generally accompanied by feelings of sadness and emptiness. Very often, people suffering from depression lose interest in the activities they used to enjoy and slip into an increasingly negative perception of themselves, sometimes culminating in a profound sense of uselessness or even guilt.
Physically, depression is accompanied by difficulties in concentrating and sleeping well, leading to the associated problems of chronic fatigue and memory loss. Depression can also be accompanied by loss of appetite, weight loss or gain, and the appearance of often unexplained aches and pains such as headaches.
Can depression cause hair loss?
It has now been established that people suffering from depression are more likely than others to suffer from diabetes, cardiovascular disease and even Alzheimer's disease.
With regard to hair loss, no direct link has been established by serious scientific studies.
Nor does our experience at Clauderer allow us to say: "Yes, hair loss is a direct consequence of depression".
On the other hand, the experience we can share with certainty is that depression, when prolonged, can indirectly lead to a hair loss simply because of the high levels of stress it generates in the sufferer.
Well, yes, a high level of stress can certainly cause hair loss.
In our experience at Centre Clauderer, hair loss caused by high levels of stress as a result of depression can take several forms:
Telogen effluvium :
This is the most common form of hair loss. In concrete terms, hair loss is observed all over the scalp, as if the body were putting the hair into a resting period. Hair grows more slowly. It falls out prematurely when it is combed or washed.
Trichotillomania :
Depression can be accompanied by feelings of frustration or anxiety that have no outlet. People suffering from depression may develop trichotillomania (although this is fairly rare), which is a compulsive urge to pull out body hair.
And finally... alopecia areata :
Severe stress is one of the many potential causes of alopecia areata, a condition in which the body's immune system appears to attack hair follicles, inducing hair loss in highly targeted areas. It's an observation. A condition whose mechanisms are currently unexplained.
Finally, it should be remembered that many drugs prescribed to combat depression have the undesirable side-effect of hair loss. None of them, however, mention the appearance of alopecia areata.
How to stop alopecia
There is currently no fully recognised, universal treatment for alopecia areata..
Japanese doctors are exploring two types of treatment: topical immunotherapy and corticosteroids.
It is important to stress that patients undergoing treatment with these drugs must be constantly monitored clinically because of the very frequent adverse effects they can cause. The most common include weight gain, high blood pressure, diabetes, sleep disorders and the onset of allergies.
In children, treatment options are even more limited, given the potentially serious side-effects induced by the treatment. Why take a therapeutic risk when most cases of alopecia areata in children disappear spontaneously?
Jean-François Cabos is the creator of a unique hair care method based on the research he coordinated, which led to the publication of the book Hair, Roots of Life with Hélène Clauderer published by Robert Laffont (Collection "Réponses/ Santé").
