The term ‘personality difficulty’ will be unfamiliar to most people except as a general concept, but it will be part of the ICD-11 diagnostic spectrum of personality disorder in January 2022. We know a fair deal about it, but it is not a diagnosis. It is listed in the section of the ICD-11 classification for ‘non-disease entities that constitute factors, influencing health status and encounters with health services, that may be of clinical importance’, called Q Factors. The important section for personality difficulty is QE50 (problems associated with relationships). The full QE50 list is shown in Table 3.1.