Gender Incongruence (GI) is a rare condition in adolescence characterized by a marked incongruence between one's experienced gender and the assigned sex. It presents as a combination of: a strong discomfort and/or intense rejection of the behavior/attributes of the born gender, a strong desire to live (and be treated) of the experienced gender, and/or a determination to follow the process of transition (i.e. hormonal therapy, sex reassignment surgery). Psychological functioning and treatment outcome has shown significant variation across transgender individuals.

This study aimed to investigate the diagnostic stability of GI in adolescents across ICD-10, DSM-IV-TR, DSM-5, and ICD-11.

Case series of four adolescents aged 16-17 (3 female-born and 1 male-born) with GI seen at Child and Adolescent Mental Health Services (London, UK) in 2012, who completed clinical assessments and questionnaires (Utrecht Gender Dysphoria Scale and Gender identity/GD questionnaire for adolescents and adults).

GI diagnostic criteria varied across diagnostic systems regarding: (1) number of indicators required, (2) symptoms duration, and (3) presence of clinical distress/impairment. In our case series, the latter led to diagnostic instability: two adolescents did not fulfill DMS-IV-TR and DSM-5 criteria. Nonetheless, the dimensional approach supported the GI diagnosis for the four adolescents.

Classification systems evolved in their conceptualization of GI over time evidenced by a shift in the condition name and diagnostic criteria. Diagnostic instability across classification systems may have an impact on their clinical utility. Evidenced-based investigations are required to further assess the clinical utility of the new classification systems.