The term deaf (lower case) describes someone who has severe audiological problems. People who have a strong Deaf cultural identify and use their national sign language, identify themselves as a cultural and linguistic community, distinguished by using Deaf (uppercase). The sections within this thesis generally adopt the term deaf to incorporate a wide understanding of people who are currently experiencing deafness.

Section one presents a mixed methods systematic literature review identifying how symptoms of schizophrenia spectrum disorders (SSD) present in prelingually deaf people. Five databases were systematically searched, and 21 studies were included in a narrative synthesis. Findings highlighted that symptoms of SSD may present differently in prelingually deaf populations. It may be more difficult to separate delusions and hallucinations in prelingually deaf SSD and language deficits may be seen with or without thought disorder. The review identified that there is a small, but dedicated evidence base which requires attention from more methodologically rigorous research in the future.

Section two details an empirical investigation of the relationship between intimate partner violence (IPV) victimisation, adult attachment style, early language experiences, and psychological wellbeing in deaf people. Participants (N = 63) completed an online survey comprising of self-report measures. High levels of IPV were reported in the sample. Hierarchical regression models of IPV, attachment style, and early language experiences did not significantly predict well-being, although attachment avoidance was positively associated
with IPV victimisation. Small sample size increased the likelihood of type II error.

Discussion of the results considered that the unique language experiences and communication needs of deaf populations are likely to represent a range of factors that influence the power imbalances within IPV victimisation.

Section three includes a critical appraisal, which highlights some of the practical,
ethical, and methodological issues encountered throughout the development of sections one and two.