In the few studies that have been conducted, researchers have typically found that deaf adolescents have more mental health difficulties than their hearing peers and that, within the deaf groups, those who use spoken language have better mental health functioning than those who use sign language. This study investigated the hypotheses that mental health functioning in adolescence is related to an early and consistent mode match between mother and child rather than to the child's use of speech or sign itself. Using a large existing 15-year longitudinal database on children and adolescents with severe and profound deafness, 57 adolescents of hearing parents were identified for whom data on language experience (the child's and the mother's) and mental health functioning (from a culturally and linguistically adapted form of the Achenbach Youth Self Report) was available. Three groups were identified: auditory/oral (A/O), sign match (SM), and sign mismatch (SMM). As hypothesized, no significant difference in mental health functioning was found between the A/O and SM groups, but a significant difference was found favoring a combined A/O and SM group over the SMM group. These results support the notion of the importance of an early and consistent mode match between deaf children and hearing mothers, regardless of communication modality.