This thesis aimed to explore interventions and nurse-patient relationships in acute mental health inpatient settings. Three separate papers are presented in this thesis: a systematic literature review, an empirical paper and a critical evaluation of the first two papers. Paper 1- This systematic review aimed to investigate clinically trialled psychosocial interventions for patients admitted to inpatient settings; and to identify which were effective at improving quality of life, symptoms or patient functioning. Eighteen were identified, fifteen studies showed a statistically significant positive impact on at least one outcome. Seven intervention categories (animal assisted therapy, music therapy, progressive muscle relaxation, education-based interventions, talking therapies, training-based interventions and cognitive remediation) and at least one study in each category was found to be effective. Methodological quality was generally low, and the small number of available RCTs makes it difficult to draw definitive conclusions. Further research is required of psychosocial interventions for acute mental health inpatient wards which use more rigorous methods of testing and reporting trials. Paper 2-To explore patient social functioning and nurse distress in relation to nurse-patient alliance, emotional regulation and attachment style in acute mental health inpatient wards. Patient anxious attachment style was significantly associated with difficulties in regulating emotions. Patient social behaviour was predicted by emotion regulation, attachment and alliance, but was not predicted by nurse emotion regulation, nurse attachment style or nurse-rated alliance. Nurse distress was associated with nurse emotion regulation, nurse anxious attachment and nurse-rated alliance, these factors also predicted nurse distress. Paper 3-The aim of the critical evaluation is to provide a critical appraisal of the design, implementation and interpretation of the findings for Papers 1 and 2. Strengths and challenges for both papers are discussed, and personal reflections about the thesis process are included.