In adolescents, the diagnosis of gender dysphoria is a delicate matter, as it occurs during a period of hormonal upheaval, physical changes, and psychic discomfort. Pediatric, endocrinological, and even surgical treatment will depend on this diagnostic decision. The diagnostic confirmation of gender incongruence is all the more important as it will lead to individualized and personalized follow-up care. We have therefore tried to determine how to understand this entanglement of nosological frameworks in the period of adolescence. Caution should be exercised when gender incongruence turns out to be associated with a personality or psychiatric disorder, the instability of which may cause confusion among caregivers. The co-occurrence relationship between psychiatric disorders and gender dysphoria, from a clinical (not statistical) perspective, appears to be particularly difficult to disentangle. However, careful consideration can provide adequate information, a precise diagnosis, and personalized follow-up care.