There is a significant body of evidence reporting that parents of children with intellectual disabilities are more stressed than parents of typically developing children. However, previous research has also highlighted large variations in the levels of stress and other problems reported by parents. There is increasingly a move towards exploring the existence and nature of bi-directional relationships that occur between parental stress and variables such as child behaviour. This thesis aimed to further assess this longitudinal relationship but with the inclusion of a number of unique features. First, a model was proposed to guide the research and the analysis. This incorporated aspects of a number of
influential models in the stress and coping literature. Second, a variety of child measures were included that examine multiple aspects of a child's development. Third, it featured both positive and negative outcomes. Fourth, potential mediating and moderating processes were investigated. Analyses were conducted at two time points and an observational study was completed after the main data collection. 138 mothers and 60 fathers took part at Time 1 whilst 113 mothers and 50 fathers took part at Time 2. The participating families completed a series or questionnaires at both time points and were interviewed over the phone. T-tests and bivariate correlations were used to investigate basic relationships amongst the variables and the both the cross-sectional (Time 1) and longitudinal (Time 1 and Time 2) data were analysed using regression analyses. In the observational study, 20 mothers participated, and were visited at their home. They completed a standard play task with their child and this was recorded by the research team. The data were analysed using t-tests and bivariate correlations. Child psychopathology was found to significantly predict parental stress over time, but no longitudinal relationship was found. Stress, coping and support were found to significantly predict both positive and negative parental outcomes with a number of bi-directional effects observed. A number of mediating and moderating relationships were also found, with wishful thinking coping strategies featuring strongly. The implications of the results are discussed, with reference to future research and clinical implications.