Hi You can find most things like this on the HSE web site, as they are the legal body. Here is a direct quote. "No, neither work related stress nor stress-related illnesses are reportable under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1995 (RIDDOR). This is because the causes of stress-related ill health are usually extremely complex and linking conditions to specific types of work activity would be very difficult. This does not mean that stress cannot be raised with the enforcing authorities nor does it mean that a complaint cannot be made which could result in an investigation. While work related stress is not reportable, employers have duties to assess and manage the risk of stress-related ill health arising from work activities." Ian

Stress is never reportable, even when it may result in an over 7 day abasence, even if there may be some or significant "work-relatness" to it, as is not an "injury" . It is also not in the list of diseases. Thr HSE Website confirms this http://www.hse.gov.uk/stress/faqs.htm#q13