Qualités psychométriques de la version française de la TAS-20 et prévalence de l'alexithymie chez 264 adolescents tout-venant [The 20-item Toronto alexithymia scale: structural validity, internal consistency and prevalence of alexithymia in a Swiss adolescent sample]

L'objectif de cette étude est d'examiner la structure factorielle et la consistance interne de la TAS-20 sur un échantillon d'adolescents (n = 264), ainsi que de décrire la distribution des caractéristiques alexithymiques dans cet échantillon. La structure à trois facteurs de la TAS-20 a été confirmée par notre analyse factorielle confirmatoire. La consistance interne, mesurée à l'aide d'alpha de Cronbach, est acceptable pour le premier facteur (difficulté à identifier les sentiments (DIF)), bonne pour le second (difficulté à verbaliser les sentiments (DDF)), mais en revanche, faible pour le troisième facteur (pensées orientées vers l'extérieur (EOT)). Les résultats d'une Anova mettent en évidence une tendance linéaire indiquant que plus l'âge augmente plus le niveau d'alexithymie (score total TAS-20), la difficulté à identifier les sentiments et les pensées orientées vers l'extérieur diminuent. En ce qui concerne la prévalence de l'alexithymie, on remarque en effet que 38,5 % des adolescents de moins de 16 ans sont considérés comme alexithymiques, contre 30,1 % des 16-17 ans et 22 % des plus de 17 ans. Notre étude indique donc que la TAS-20 est un instrument adéquat pour évaluer l'alexithymie à l'adolescence, tout en suggérant quelques précautions étant donné l'aspect développemental de cette période.

Genome-wide association analysis identifies 20 loci that influence adult height.

Adult height is a model polygenic trait, but there has been limited success in identifying the genes underlying its normal variation. To identify genetic variants influencing adult human height, we used genome-wide association data from 13,665 individuals and genotyped 39 variants in an additional 16,482 samples. We identified 20 variants associated with adult height (P < 5 x 10(-7), with 10 reaching P < 1 x 10(-10)). Combined, the 20 SNPs explain approximately 3% of height variation, with a approximately 5 cm difference between the 6.2% of people with 17 or fewer 'tall' alleles compared to the 5.5% with 27 or more 'tall' alleles. The loci we identified implicate genes in Hedgehog signaling (IHH, HHIP, PTCH1), extracellular matrix (EFEMP1, ADAMTSL3, ACAN) and cancer (CDK6, HMGA2, DLEU7) pathways, and provide new insights into human growth and developmental processes. Finally, our results provide insights into the genetic architecture of a classic quantitative trait.

Secular trends in legal and illegal substance use among 16 to 20 year old adolescents in Switzerland.

BACKGROUND: Data targeting trends in legal and illegal substance use by adolescents are scarce. Using the data from two similar large national surveys run in 1993 and 2002, this paper assesses secular trends in rates of substance use among 16-20-year-old Swiss adolescents. METHODS: Self-reported regular use of tobacco, alcohol misuse, regular cannabis use (01 occasion over last 30 days) and lifetime use of psychoactive medication, LSD, ecstasy, cocaine and heroine were assessed through identical questions using an anonymous self-administered questionnaire. 9268 (1993) and 7428 (2002) high school students and apprentices were included in the analyses. RESULTS: There is a higher proportion of regular smokers among apprentices than among students (p <0.001). Between 1993 and 2002 the increase in regular tobacco consumption was significant among both female and male apprentices (p <0.001) but not among students. Between 1993 and 2002 alcohol misuse significantly increased in all four groups (p <0.001). It is more prevalent among males than among females (p <0.001) and higher among apprentices than among students (p <0.001). Regular use of cannabis has increased in the four groups (p <0.0001). It is higher among males than among females (p <0.001), while it is largely the same among students and apprentices. While the increase in ecstasy use is highly significant in all four groups (p <0.001), the increase in LSD and cocaine use is significant among apprentices only (p <0.001). Use of LSD, ecstasy and cocaine is more prevalent among males than among females (<0.001) and higher among apprentices than among students (p <0.001). CONCLUSION: The secular increase in psychoactive substance use among older Swiss adolescents calls for the implementation of effective strategies both from individual and public health viewpoints.