Although past research provided some clues about the relation of language use with mental health, the mediatory functions of personality variables in this relationship have been ignored. This research examined the mediatory role of self-concept clarity in the relationship between language use perceived by individuals and mental health indicators including anxiety, depression, and alexithymia. Based on the theoretical framework suggested by Simsek (2010), two studies sought to test two alternative structural equation models in data from university students in the first study (n = 250) and data from other groups in the second study (n = 331). The first model assumed that the relationship of language use with anxiety, depression, and alexithymia was mediated by self-concept clarity. The second model tested the mediatory role of both anxiety and self-concept clarity in this relationship. The results of the first study showed that the second model fitted better to the data than the first. Consistent with the first study, the results of the second study confirmed that the second model produced better goodness of fit statistics than the first model.