L’adolescence est un moment singulier du processus de maturation de l’individu ; les médicaments psychotropes peuvent avoir chez l’adolescent des profils d’efficacité et de tolérance différents de ceux notés à d’autres âges de la vie. Limitant notre propos à une seule classe pharmacologique, nous nous posons dans ce travail la question suivante : dans quelles indications et selon quelles modalités les thymorégulateurs devraient-ils être prescrits aux adolescents ?

Le lithium dispose de la plus ancienne autorisation de mise sur le marché (AMM) en France et aux États-Unis dans le cadre du trouble bipolaire à l’adolescence ; il présenterait également, hors AMM, un intérêt dans les troubles du comportement. Le lithium nécessite une surveillance biologique régulière et exige une bonne observance. Aucun anticonvulsivant ne possède l’AMM dans le cadre du trouble bipolaire à l’adolescence ; pourtant l’American Academy of Child and Adolescent Psychiatry (AACAP) recommande le divalproate de sodium comme un des traitements de première intention de la manie. Enfin, les antipsychotiques de deuxième génération (ADG) ont obtenu une AMM pour le trouble bipolaire : en France, uniquement l’aripiprazole, mais aux États-Unis également la rispéridone, l’olanzapine et la quétiapine. De plus, les ADG figurent dans les recommandations consacrées aux troubles du comportement de l’adolescent et publiées par l’AACAP et le National Institute for Health and Clinical Excellence. Leurs effets secondaires sont métaboliques, moteurs et cognitifs.

Les données épidémiologiques de prescription de psychotropes se trouvent partiellement en concordance avec les recommandations précitées. D’une part, il existe effectivement une tendance pour un usage préférentiel des ADG, mais d’autre part, le lithium n’est quasiment pas prescrit chez l’adolescent, plus rarement que les anticonvulsivants (à visée thymorégulatrice). Ainsi, malgré l’absence d’AMM, ces dernières molécules sont parfois préférées au lithium – en raison de sa dangerosité en cas d’inobservance ou d’intoxication volontaire –, ou aux ADG – en raison de leur profil de tolérance. En tout cas, quel que soit le médicament prescrit, une question cruciale est celle de l’observance et de l’alliance thérapeutique, avec l’adolescent mais aussi avec ses parents.

Adolescence is a unique phase of the human developmental process. In adolescents, psychotropic medications may have different efficacy and tolerance profiles compared to those at other stages of the lifespan. Mood stabilizers are a complex pharmacological category including lithium, some anticonvulsants, and some second generation antipsychotics. Focusing on this class of pharmacological agents, we aim to answer the following questions: in which indications and according to which modalities should mood stabilizers be prescribed during adolescence?

Information was sought from the websites of the French Haute Autorité de santé (HAS) and Agence nationale de sécurité du médicament et des produits de santé (ANSM), the American Food and Drug Administration (FDA) and the British National Institute for Health and Clinical Excellence (NICE). Guidelines from the American Academy of Child and Adolescent Psychiatry (AACAP) were also reviewed. Additional articles were found using PubMed and Google Scholar. We assumed that guidelines published by a national institute were the most relevant, second information from medical academies, then literature reviews, and finally single studies. Practical prescription data were also sought from the French Vidal Drug Dictionary.

For bipolar disorder in adolescents, lithium has been the first drug licensed in France (from the age of 16) and in the USA (from the age of 12), with indications for acute mania and preventive treatment. Benefits for impulsive and self-aggressive behaviour disorders (especially relevant in case of borderline personality disorder) have also been documented, although lithium has not been licensed in any country for those indications. Extended-release tablets are usually used, at doses targeting for a lithiemia between 0.8 and 1.2mEq/L 12hours after last intake. Because of a narrow therapeutic window and potential side effects (especially nephrotoxicity), lithium prescription requires regular blood tests and good treatment compliance. None of the anticonvulsants has been licensed by a national drug administration as a mood stabilizer in adolescents. However, the AACAP recommends valproate as a first line treatment for mania, even though the NICE and the ANSM caution that valproate should not be used by women of child bearing age. Besides its teratogenic and endocrine side effects, valproate exposes one to the risk of hepatic toxicity. That is why regular liver function tests should be prescribed when valproate is chosen. According to the AACAP, carbamazepine (which is licensed for the treatment of mania in adults) is not a first line treatment for adolescents. Indeed, no clinical study has demonstrated its efficacy on manic episodes in adolescents. Moreover, carbamazepine exposes one to the risk of agranulocytosis. Lamotrigine has not been approved for adolescents, but some studies suggest its efficacy for bipolar depression (often a treatment-resistant phase) in this age group. Major side effects are the risk of Lyell or Stevens-Johnsons syndrome (which usually occur within the first eight weeks of treatment). There is no need for biological tests, just clinical monitoring. Pharmacological interactions between lamotrigine and oral contraceptives require caution. Finally, the use of some second generation antipsychotics for bipolar disorder in adolescents has been approved by national drug administrations. In France, only aripiprazole is licensed for acute mania (from the age of 13). In the USA, aripiprazole is licensed from the age of 10 for acute mania and preventive treatment, while risperidone and quetiapine are licensed from the age of 10 for acute mania, and olanzapine is licensed from the age of 13 for acute mania. The AACAP recommends second generation antipsychotics as a first line treatment for bipolar disorder. Moreover, the AACAP and the NICE recommend second generation antipsychotics for behavioural disorders in adolescents. Recommended doses are usually lower and titration slower than for adults. As in adults, adverse effects are metabolic, motor and cognitive disorders. Moreover, hyperprolactinemia, sedation and weight gain are more frequent than in adults.

Epidemiologic data for prescription of mood stabilizers in adolescents only partially concord with recommendations from drug administrations and scientific societies. On the one hand, there is a trend toward preferential prescription of second generation antipsychotics, on the other hand lithium is hardly prescribed to adolescents, less often than anticonvulsants. Thus, without approval from any drug administration, the anticonvulsants are often preferred to lithium (because of lithium's potential risks due to noncompliance or voluntary poisoning) and to second generation antipsychotics (because of their tolerance profile). Nevertheless, for prescribers it is a complex matter to compare side effects: the frequency and intensity of adverse effects is quite variable from one mood stabilizer to another, and such a thing as an expected value is therefore hard to define. Regardless of the medication chosen, compliance and therapeutic alliance are major issues. Compliance is especially low during adolescence (less than 40% according to a study on bipolar disorder). This lack of compliance has multiple determinants: poor acceptance or misunderstanding of the psychiatric disorder, indirect effects of bad relationships with parents and more generally adults, but also reckless behaviour or death wishes. Improving therapeutic alliance appears as a major challenge for health practitioners dealing with youth. One interesting path of research could be the therapeutic education programs using humanistic communication techniques (addressing both adolescents and their parents) which have already produced encouraging results.