The purpose of this study was to explore the issue of adherence to treatment for Cystic Fibrosis (CF) in adolescence. Poor adherence may lead to accelerated deterioration, increased frequency of hospital admissions, outpatient appointments and reduced ability to predict the efficacy of treatments. Several studies have shown adherence tends to decrease during adolescence (Gudas et al 1991; Patterson et al 1993). The literature, however, has repeatedly concluded that the influences upon adherence are elusive and highly complex, indicating the need for in depth qualitative study of this issue. The grounded theory method (Strauss and Corbin 1990) was used to generate a substantive theory from the accounts of eleven young people who suffer from CF, aged between ten and eighteen years. The theory is described in terms of the sufferer needing to 'bridge the gap' between normality and difference effectively. It is as if the sufferer and his/her family could be visualised as standing with one foot either side of a broken swing bridge. In order to survive they have to keep their balance. Illness symptoms and treatment serve to pull the sufferer to one side or the other at different times. The strategies used to manage the gap can be learned from the familial response to the disease. The beliefs the sufferer develops in relation to the illness and the value of treatment can provide him/her with the tools to maintain a balance in a variety of circumstances. The theory 'bridging the gap' is discussed in terms of the current literature pertaining to adherence to treatment for CF and speculation regarding its intersection with attachment theory. The potential implications for clinical intervention generated through the relating of the two theories are considered.