In their Self-Determination Theory (SDT), Deci and Ryan (1985) posit autonomy, competence, and relatedness as three intrinsic needs that contribute to well-being throughout the lifespan. Addressing the argument that the universality with which SDT makes its predictions may ignore critical developmental differences, Ryan and Deci (2000) contend that although these three needs are developmentally persistent, their relative salience may in fact vary across the lifespan. This became apparent with the finding that fulfillment of some needs was inconsequential in the prediction of depressive symptoms in a sample of children and that the experience of a balance of overall need satisfaction across important life contexts accounted for well-being over and above individual need satisfaction in a sample of adolescents (Milyavskaya et al., 2009;Veronneau, Koestner, & Abela, 2005). Despite these advances, a concrete examination of the relative salience of intrinsic needs has yet to be examined in a developmentally comparative manner. Thus, the objective of this thesis was to test the applicability of SDT across developmental periods by differentiating children and adolescents on the importance of individual needs (i.e., autonomy, competence, relatedness) and the role of balance across contexts (i.e., home, school, peers) in predicting depressive symptoms.

Non-suicidal self-injury (NSSI) is a public health concern that affects young adults at alarming rates. The present study examines the role of satisfaction of self-determination theory's three basic needs for autonomy, competence, and relatedness in young adults' NSSI engagement. University students who reported ever having engaged in NSSI (n = 40, 85 % female; Mage = 20.10, SD = 1.66) reported significantly lower levels of the satisfaction of all three needs, as well as more difficulties with all aspects of emotion regulation (non-acceptance of emotional responses, difficulty engaging in goal directed behavior, impulse control, lack of emotional awareness, limited access to regulation strategies, lack of emotional clarity), compared to students with no history of NSSI (n = 46, 91 % female; Mage = 19.79, SD = 1.37). Results of a logistic regression analysis revealed that need satisfaction added to the prediction of NSSI group membership after controlling for the effects of emotion regulation. Satisfaction of the need for competence and limited access to emotion regulation strategies accounted for significant variance in NSSI in the final model. The findings suggest that self-determination theory may be a useful framework under which to conceptualize NSSI and that the need for competence may be particularly salient for University students.

While previous research has demonstrated cross-national differences in non-suicidal self-injury (NSSI), most studies to date have taken place in North America. The present study investigated the prevalence and characteristics of NSSI in a sample of 952 Jordanian adolescents (49.8% female) between the ages of 11-19 years. Participants completed a screening measure to assess occurrence of NSSI and its characteristics. Results indicate an overall lifetime prevalence of 22.6% (n = 215), with significantly more males (26.98%, n = 129) than females (18.14%, n = 86) reporting having engaged in NSSI at least once in their lifetime. This study provides empirical evidence that adolescent engagement in NSSI occurs at similar prevalence levels in Jordan, relative to North American samples, whereas gender comparisons of prevalence and characteristics revealed several differences.

Adolescents who do not perceive autonomy support from their parents, have more difficulties regulating their emotions, and may turn to NSSI as a means to cope. Clinical implications of the findings suggest involving the family, and specifically, targeting parental autonomy support may be beneficial when working with young adolescents who self-injure. (PsycINFO Database Record

The present study applied self-determination theory to examine the onset, maintenance, and cessation of non-suicidal self-injury (NSSI) in adolescents. Specifically, the study examined the relationship between the basic psychological needs of autonomy, competence, and relatedness, and NSSI status. Participants were classified into the NSSI Maintain (n = 30), NSSI Start (n = 44), NSSI Stop (n = 21), or Control (n = 98) groups based on NSSI status over 2 time points within a 12-month period. Repeated measures multiple analysis of variance was employed. Satisfaction of the need for competence decreased over time in all adolescents. Adolescents who maintained NSSI behavior reported significantly lower levels of need satisfaction compared to adolescents reporting no history of NSSI engagement, and adolescents who began NSSI over the course of the study reported significantly lower levels of need satisfaction compared to those reporting no history of NSSI engagement. The findings suggest that need satisfaction varies as a function of NSSI status.