Background:The prevalence of mental health difficulties in d/Deaf populations is higher thanthat of the hearing population. The association between mental health difficultiesin childhood and well-being in adulthood amongst d/Deaf populations, including asperceived by Deaf people themselves, has been little explored. Access by d/Deafpeople to mental health services is poor. In addition, there is a paucity of mentalhealth assessments available in British Sign Language.Aims:The aims of this thesis were; (i) to understand the association between childhoodand adulthood mental well-being in d/Deaf populations; (ii) to find out how well thestandardised mental health assessments can be used with d/Deaf populations;and (iii) to explore Deaf people's perspectives on mental well-being.Methods:BSL versions of four mental health assessments (the Clinical Outcomes in RoutineEvaluation - Outcome Measure (CORE-OM), the Patient Health Questionnaire(PHQ-9), the Generalized Anxiety Disorder (GAD-7), and the Work and SocialAdjustment Scale (WSAS)) were produced by carrying out a translation process toensure that the statements in the assessments are linguistically and culturallymeaningful to a Deaf population. The reliability and validation of the mental healthassessments were examined by piloting them with d/Deaf populations. In order togain Deaf people's own perspectives on mental well-being, four focus groups wereset up in England.Results:Thematic analysis of the focus group data identified pre-disposing factors inchildhood that Deaf participants believed would affect adult mental well-being.The CORE-OM BSL, PHQ-9 BSL, GAD-7 BSL, and WSAS BSL were found to bereliable and have been validated. The pilot study which compared the reliabilitybetween the BSL and English version of one mental health assessment (CORE-OM)as completed by d/Deaf people found that two domains had lower reliability inEnglish in comparison with the BSL version.Conclusions:Reliable standardised instruments in BSL are required to identify and assesscommon mental health problems amongst Deaf people. These are now available.Deaf people identified a number of factors that are important to well-being, forexample, ease of communication with others, a strong sense of identity, a 'can do'attitude, and a firm sense of belonging. These factors are of importance if we areto attempt to reduce the prevalence of mental health difficulties in d/Deafpopulations in the future.