Increase in diagnosis of depressive disorders contributes to the increase in antidepressant use in adolescents.

OBJECTIVE: To study if the observed increase in use of antidepressants (AD) among adolescents may be explained by higher incidence of depressive disorder diagnosis, increasing treatment of other mental disorders or more liberal prescribing practice. METHODS: We used three different study populations of girls and boys aged 13-17 years in Norway: 1) individuals who were diagnosed with depressive disorders in primary health care, 2) individuals who were diagnosed with depressive disorders in secondary health care; 3) individuals who were dispensed ADs as recorded in the prescription database. Dataset 2) and 3) were linked. RESULTS: Incidence of depressive disorders increased from 2010 to 2015 both in primary and secondary health care, especially in girls. One in four girls with incident depressive disorders was prescribed ADs and this proportion was stable over time. Among girls treated with ADs the proportion with a diagnosis where AD treatment is indicated increased from 61.1% to 66.0%. Furthermore, the proportion with moderate or severe episodes of major depressive disorders was stable and high, 72.9% in 2014. CONCLUSION: The only issue studied that could explain increasing AD use in girls was increasing incidence of depressive disorders. Most adolescents with incident diagnosis of depressive disorders were not treated with ADs.

Antidepressant drug use among adolescents during 2004-2013: a population-based register linkage study.

OBJECTIVE: To study trends in use of antidepressants (ADs) by adolescents, and psychiatric morbidity and use of other psychotropic drugs as a measure of psychiatric comorbidity. METHODS: One-year prevalence of AD drug use was analyzed for 13- to 17-year-old Norwegians during 2004-2013. Use of other psychotropic drugs and specialist healthcare services was analyzed for incident AD users in 2012, using linked data from the Norwegian Prescription Database and the Norwegian Patient Register. RESULTS: The 1-year prevalence of AD drug use increased from 6.4/1000 to 9.1/1000 during 2004-2013, with the steepest increase from 2010, particularly among girls. The highest prevalence was found in 17-year-old girls (17.8/1000 in 2010, 27.5/1000 in 2013). Of incident AD drug users in 2012, 84.4% had been in contact with specialist health care. As the first drug, 78.4% were prescribed a selective serotonin reuptake inhibitor. The most common types of other psychotropic drugs were melatonin (24.6%), antipsychotic drugs (13.2%), stimulants (8.8%), and anxiolytics (6.0%). CONCLUSIONS: Use of ADs among adolescents has increased over the last 3-4 years, particularly among 16- to 17-year-old girls. A total of 85% of incident users had been in contact with specialist health care, which may indicate that drug-therapy is used by adolescents with more severe symptoms.

Detection of one single mutation predicts thiopurine S-methyltransferase activity in a population of Saami in northern Norway.

Thiopurine S-methyltransferase (TPMT) activity exhibits genetic polymorphism. The purpose of this investigation was to identify TPMT mutant alleles in the Saami population as a basis of developing genotyping tests for prediction of TPMT activity. The most predominant allele in Saamis (n = 194) was the TPMT*3C allele (A719G mutation) representing 92% of the mutant alleles, with an estimated allelic frequency of 3.3%. The most frequent allele in Caucasians (n = 66) living in the same geographic area was the TPMT*3A (A719G and G460A mutations) representing 91% of the mutant alleles, with an estimated allelic frequency of 3.4%. A test for one mutation, A719G, may prospectively identify more than 90% of the Saami individuals who require reduction in thiopurine dose to avoid hematopoietic toxicity. In a Norwegian population, comprising both the major Caucasian population and a minor Saami population, the same genotyping tests (eg, tests for the A719G and G460A mutations) may be used.