The perceived fit of guided iCBT in specialised mental healthcare services: a qualitative study of healthcare professionals' perspectives.

Background: Therapist-guided internet-delivered cognitive behavioural therapy (guided iCBT) is an effective treatment for common mental disorders and has the potential to improve access to care. However, its integration into routine practice remains limited. This study explored healthcare professionals' perceptions of the suitability of guided iCBT in specialised mental healthcare and examined how perceived fit influences implementation across clinical and organisational contexts. Methods: Semi-structured interviews and participatory observations were conducted at three specialised mental health clinics in Norway that offered guided iCBT to adults with anxiety and depression. Thirty-one healthcare professionals were recruited through purposive and snowball sampling. Data were analysed using a combination of inductive and deductive approaches. The deductive analysis was informed by Lau et al.'s framework of contextual fit, which conceptualises fit as alignment between an intervention and professional, organisational, and external contexts. Results: Healthcare professionals' perceptions of fit varied across contextual levels and influenced the implementation of guided iCBT. At the intervention level, participants identified a perceived mismatch between the evidence base for guided iCBT and limitations in its technological design, which was viewed as insufficiently aligned with contemporary therapeutic practices. At the professional level, differing professional values and therapeutic norms shaped perceptions of appropriateness and acceptability. At the organisational level, limited readiness for implementation and concerns about patient complexity in specialised care settings contributed to doubts about the intervention's suitability. At the external level, tensions emerged between evidence-based expectations and prevailing clinical assumptions favouring face-to-face care, further affecting perceptions of fit and legitimacy. Conclusions: The findings suggest that implementing guided iCBT in specialised mental healthcare depends on aligning the intervention with the clinical, organisational, and broader system contexts in which it is introduced. Efforts to improve technological usability, strengthen organisational readiness, engage clinicians, and address assumptions about legitimate forms of therapy may enhance perceived fit and support sustained implementation of guided iCBT.