Confirming the etiology of adolescent acting-out behaviors: an examination of observer-ratings in a sample of adoptive and biological siblings

Background: A recent meta‐analysis revealed moderate shared environmental influences (C) on most forms of child and adolescent psychopathology ( Burt, 2009 ), including antisocial behavior. Critically, however, the research analyzed in this meta‐analysis relied largely on specific informant‐reports (and particularly parent and child reports), each of which is subject to various sources of rater bias. Observer‐ratings of children’s behaviors avoid many of these biases, and are thus well suited to verify the presence of C. Given this, we sought to buttress the evidence supporting C in two key ways. First, we sought to confirm that C contributes to observer‐ratings in a sample of adoptive siblings, as similarity between adoptive siblings constitutes a ‘direct’ estimate of C. Second, we sought to confirm that these shared environmental influences persist across informants (i.e., the effects are not specific to the rater or the context in question). Methods: The current study examined the etiology of observer‐ratings of acting‐out behaviors, as well as sources of etiological overlap across observer‐ratings, adolescent self‐report and maternal‐report in sample of over 600 biological and adoptive sibling pairs from the Sibling Interaction and Behavior Study (SIBS). Results: Results revealed moderate and significant shared environmental influences on observer‐ratings (31%), as well as on the other informant‐reports (20–23%). Moreover, a portion of these effects overlapped across measures (C correlations ranged from .32 to .34). Conclusions: Such findings argue against passive gene–environment correlations (rGE) and rater bias as primary explanations for earlier findings of C on antisocial behavior, and in this way, offer a critical extension of prior work indicating that the role of shared environmental influences on child and adolescent antisocial behavior was dismissed too soon.     

Leishmaniasis treatment—a challenge that remains: a review

Leishmaniasis is a disease caused by flagellate protozoan Leishmania spp. and represents an emergent illness with high morbidity and mortality in the tropics and subtropics. Since the discovery of the first drugs for Leishmaniasis treatment (i.e., pentavalent antimonials), until the current days, the search for substances with antileishmanial activity, without toxic effects, and able to overcome the emergence of drug resistant strains still remains as the current goal. This article reports the development of new chemotherapies through the rational design of new drugs, the use of products derived from microorganisms and plants, and treatments related to immunity as new alternatives for the chemotherapy of leishmaniasis.