Specific diagnoses have specific implications, and this chapter examines these. Prevalence of specific conditions is difficult to establish, but some broad findings are reviewed. Specific diagnoses are then considered in turn, looking at their conceptual basis and potential misunderstandings, diagnostic criteria and the difficulty of categorising symptoms, and the implications of making, or not making, each.For each diagnosis the authors consider how culturally normal reactions may wrongly be labelled as ‘symptoms’ but equally how problems may be wrongly ascribed to ‘culturally normal’ experience. Some diagnoses may be overlooked, especially if difficulties are ascribed to cultural factors – substance abuse, traumatic brain injury, intellectual disability and neuroatypicality.

Situations where there is no diagnosis, or changing and overlapping diagnoses are reviewed.Fabrication is considered, and the value and hazards of raising the possibility in an assessment.