In the last two decades, the medical understanding of Cystic Fibrosis (CF) has dramatically improved, however, there are still significant gaps in our understanding of the psychological adjustment of families coping with CF. We examined the utility of the Social Cognitive Processing (SCP) Model in understanding the interactions of parents and young people with CF. We also examined the relationship between social constraints, a key construct in the SCP model, sense of coherence (SOC) and other psychological adjustment indicators for young people with CF. Participants comprised 49 individuals with CF, aged 16–25, recruited through state-based CF organisations in Australia. The results indicated that participant ratings of difficulties with communication (social constraints) were positively associated with ratings of depression, anxiety, and stress and negatively related to ratings of positive affect and seeing life challenges as predictable, manageable and meaningful (SOC). Ratings of SOC were also positively related to ratings of positive affect and negatively related to ratings of depression, anxiety and stress. A significant mediating effect of SOC was also identified in the relationships between social constraints and positive affect and social constraints and stress. The theoretical and clinical implications of these findings are discussed.