Speech, language and communication disorders are associated with greater risk for poor mental health outcomes. Adverse mental health can have a detrimental impact on educational and employment outcomes, and life chances. There has been much research examining the association between anxiety and developmental stuttering, which affects approximately 8% of children. Environmental factors commonly experienced by children who stutter, such as negative peer reactions, teasing and bullying, may put this clinical population at elevated risk of internalising problems. Yet, depression, which frequently co-occurs with anxiety and typically develops in late adolescence, has received comparatively little attention in relation to stuttering. Enhancing our understanding of the association between stuttering and symptoms of anxiety and/or depression, and the underlying mechanisms that may moderate any association, would inform timely, effective clinical management.

This thesis begins by systematically reviewing the extant literature. The second study utilises data obtained through an online questionnaire study to examine anxiety and depression symptoms in children who do and do not stutter, and analyse the association between child-, family- and contextual- factors and symptom scores in a sample of school-aged children who stutter. The final study draws on Millennium Cohort Study data to plot internalising symptom trajectories in cohort members who stutter, and considers the effect of co-occurring speech and language problems on development of internalising symptoms. The effect of multiple predictors on risk for internalising problems are then considered in a sample of adolescents who stutter.

Findings from this research indicated there was little evidence that stuttering affects internalising symptoms in a community sample. Female sex, maternal mental health, and co-occurring speech and language problems were associated with elevated internalising symptoms in children and adolescents who stutter. Clinicians need to be alert to these factors in clinical assessment and ongoing management to promote mental well-being and resilience.