["Criminal Behaviour and Mental Health, Volume 30, Issue 6, Page 341-349, December 2020. ", "\nAbstract\n\nBackground\nThe indeterminate sentence of Imprisonment for Public Protection (IPP), was created in England and Wales in 2003. After its abolition in 2012, many IPP‐prisoners have become stuck in the prison system, facing considerable problems of sentence progression. The extant literature makes clear that the uncertainty and hopelessness caused by the indeterminacy of the IPP sentence are compounded by the negative impacts experienced by families and others providing support to people serving these sentences.\n\n\nAims\nThe mental strains caused for family members by the IPP sentence were examined. Of particular interest is the role and weight of the parole process experience, and its potential mental and physiological health impact on families.\n\n\nMethods\nThis article draws on findings from two qualitative research projects conducted with families of prisoners serving the IPP sentence in England and Wales. Their experiences will be examined by reference to literature on the mental health impact of indeterminate sentences on prisoners and their families and the wider literature on the symbiotic harms of imprisonment for families. The aim was to add to this by focusing on families' experiences of cumulative stress caused by the sentence.\n\n\nFindings\nWe demonstrate that the IPP parole process exerts specific weight and mental strains on family members occupying the negative end of the stress spectrum. Drawing on a body of neuroscientific, neuroendocrinological and criminological literature, we argue that these mental health impacts on families may represent a public health risk in need of practical and policy mitigation.\n\n\nImplications\nThere is a pressing need for recognition of what are often hidden symbiotic harms experienced by families of people sentenced to IPP. Families require more information as well as considerably greater practical and emotional support on an institutional and communal level.\n\n"]