Individuals with severe or profound intellectual disabilities may be at a greater risk of developing mental health problems. Despite this, evidence suggests individuals can face difficulties in getting mental health support, and little is known about effective psychological therapies for this population. Hence, this study explored mothers' experiences of seeking mental health support for their offspring. Semi-structured interviews were conducted with six mothers of adults with severe or profound intellectual disabilities, who had sought mental health support for their offspring. Interviews were audio-recorded and analysed using Interpretative Phenomenological Analysis. The three main themes were 'A struggle to understand, Challenges to getting mental health support, and A mother's approach to adapting therapy.' Mothers found it difficult to recognise signs of emotional difficulties in their offspring. However, they thought that their offspring faced discrimination when accessing services, and that professionals often lacked the knowledge and skills to work with people with severe impairments. The mothers also stressed the importance of the therapeutic relationship and the need to involve carers in therapy. This study highlights the need for more appropriate mental health support for individuals with severe and profound intellectual disabilities. The findings also suggest further research is needed about adapting psychological therapies for this population.