Social support for Mexican-origin adolescent mothers can benefit mental health. Currently, there is little research on specific dimensions of social support and how they change during the beginning years of parenthood, and even less focusing on the influence each dimension has on adolescent mothers' mental health. This study sought to fill such gaps through the analysis of data from the Supporting MAMI Project at Arizona State University. First, the current study assessed perceptions of emotional, instrumental, and companionship support received from mother figures by Mexican-origin adolescent mothers (N = 204; Mean age at Wave 1 = 16.24, SD = .99) across five years through descriptive statistics and univariate latent growth models. Second, the study assessed the strength of the impact that each dimension of social support had on mental health across six years via conditional growth models. Findings indicated that each dimension of social support shifted in a bi-linear spline shape from Wave 1 to Wave 6, with growth parameters' significance varying for each dimension of support. Each dimension of support was significantly related to depressive symptoms at Wave 6, with varying degrees of influence across growth parameters. Implications for future research and practice are discussed.