Latent class analysis of anxiety and depressive symptoms of the Youth Self-Report in a general population sample of young adolescents

This study examined whether distinct groups of young adolescents with mainly anxiety or mainly depression could be identified in a general population sample. Latent class analysis was used on self-report ratings of DSM-IV symptoms of anxiety and depressive disorders, because it was hypothesized that these ratings provide a bigger chance to identify distinct groups than parent ratings of symptoms that are poorly associated with DSM-IV. Results from exploratory and confirmatory latent class analysis showed that only very small numbers of young adolescents had mainly anxiety or mainly depressive symptoms. Instead, a five-group model fitted the data best. These five groups contained young adolescents who either had a high, intermediate, or low probability to have comorbid symptoms of anxiety and depression. It was concluded that symptoms of DSM-IV anxiety and depressive disorders co-occur in young adolescents, and that latent class analysis on items that capture also severe symptoms like suicidal thoughts are needed to derive groups with specific comorbidity patterns in a general population sample.     

Some effects of stimulant medication on response allocation: a double-blind analysis

Children who are diagnosed with attention deficit hyperactivity disorder (or who engage in behavior consistent with such a diagnosis) are often prescribed stimulant medications for hyperactive or inattentive behaviors. However, the mechanisms by which stimulant medications affect individuals' behavior are rarely evaluated. The purpose of the current study was to evaluate the effects of stimulant medication on response allocation when antecedents and consequences were held constant and equated. Results indicated that the presence of an amphetamine medication (Adderall) influenced response allocation across two concurrently available responses while all other stimulus conditions were held constant.