Table 1. F66 categories in ICD-10: psychological and behavioural disorders associated with sexual development and orientation^a.

Codeb	Category name	Description
F66.0	Sexual maturation disorder	The individual is uncertain about his or her gender identity or sexual orientation, which causes anxiety or depression. Most commonly this occurs in adolescents who are not certain whether they are homosexual, heterosexual or bisexual in orientation and in individuals who, after a period of apparently stable sexual orientation and often within a long-standing relationship, find that their sexual orientation is changing
F66.1	Ego-dystonic sexual orientation	The gender identity or sexual preference is not in doubt, but the individual wishes it were different because of associated psychological and behavioural disorders, and may seek treatment to change it
F66.2	Sexual relationship disorder	The gender identity or sexual preference abnormality is responsible for difficulties in forming or maintaining a relationship with a sexual partner
F66.8	Other psychosexual development disorders	NA
F66.9	Psychosexual development disorder, unspecified	NA

ICD-10: International Statistical Classification of Diseases and Related Health Problems, 10th revision; NA: not applicable.

^a Sexual orientation alone is not to be regarded as a disorder.

^b The following five-character codes may be used to indicate variations of sexual development and orientation that may be problematic for the individual: F66.x0 – heterosexual; F66.x1 – homosexual; F66.x2 – bisexual (to be used only when there is clear evidence of sexual attraction to members of both sexes); and F66.x8 – other, including prepubertal, where x is the figure after the decimal point for the relevant category in the table.