A Short-Form Measure of Loneliness to Predict Depression Symptoms Among Adolescents.

The purpose of this study was to produce a short-form measure of loneliness and assesses its prediction of depressive symptoms relative to a comprehensive measure. Western Australian adolescents completed the Friendship Related Loneliness and Isolation subscales of the Perth Aloneness Scale (PALs) three times over 18 months (T 1 n = 1538; T 2, n = 1683; T 3, n = 1406). Items were reduced while preserving predictability. Follow-up confirmatory factor analyses and predictive models with the reduced and full PALs were then tested. A reduced six-item scale (PALs-6) preserved the two-factor structure of the PALs and showed strong prediction of very elevated depressive symptoms (Sensitivity = 0.70, Specificity = 0.78, AUC = 0.81); it was less successful in predicting future symptoms (Sensitivity = 0.67, Specificity = 0.64, AUC = 0.74). The PALs-6 provides a brief measure of adolescent loneliness for clinicians and researchers that also predicts very elevated levels of depression.

Screening for depressive symptoms in adolescence: A Rasch analysis of the short-form childhood depression inventory-2 (CDI 2:SR[S]).

BACKGROUND: Screening for depressive symptoms during adolescence is of high clinical significance. The shorter 12-item version of the Children's Depression Inventory (CDI 2:SR[S]) was specifically developed for this purpose. Evaluations of the CDI 2:SR[S] psychometrics are limited, however. The purpose of this study was to validate the CDI 2: SR[S] for use as a screening measure using Rasch analysis. METHODS: The CDI 2: SR[S] was administered online to 1513 10-17 year old Western Australian adolescents (635 males, 878 females) from 11 schools. Overall fit, individual item fit, local response dependence, dimensionality, operation of response categories, and differential item functioning (DIF) were examined. RESULTS: The Rasch analysis demonstrated the CDI 2: SR[S] has good reliability. Thresholds for all items were ordered, showing its three response categories functioned as intended. One item (I have to push myself to do schoolwork) showed misfit. No items were locally dependent. Two items (I am sad) and (I have to push myself to do schoolwork) showed DIF for gender. At the same level of depression, females reported being sad more than males, while males pushed themselves more to do schoolwork than did females. Adolescents (14-17 years) reported significantly higher mean depressive symptom scores than early adolescents (10-13 years). LIMITATIONS: Sole reliance on adolescent's self-report and limited data about cultural backgrounds are limitations. CONCLUSIONS: The results support the interval scale measurement properties of the CDI 2: SR[S] and provides educators, clinicians and researchers with a screening measure to assess depressive symptoms in adolescents.

Production of successive force impulses by the left and right hands.

Right-handed participants made ballistic force impulses with the index finger of their left or right hand to match the amplitude of 2 successive visual targets whose onset was separated by 600-850 ms. The targets specified either low- (10% of maximum voluntary contraction; MVC) or high- (25% MVC) force level and were presented in all combinations (low-low, low-high, high-low, high-high). The amplitude of the 1st force impulse affected that of the 2nd, forming an effect that was greatest at the shortest interresponse intervals and that decayed with increasing intervals. This effect was smaller with a shorter time course in the dominant hand than the nondominant hand, suggesting a greater ability of the dominant hand to make successive independent responses.