With over two decades of research, therapist-guided internet-delivered cognitive behaviour therapy (ICBT) is now regarded as a highly effective treatment for various mental health concerns. In this form of care, clients typically review online modules over several months and receive therapeutic support through written messages from therapists. Research shows that clients form therapeutic relationships through this method and report high satisfaction. The benefits of providing written support are multifaceted but may be underestimated. For clients, it offers flexibility, allowing them to send messages to their therapist at their convenience and to review responses at their own pace and repeatedly if needed. Written communication also provides therapeutic benefits, such as promoting emotional expression and helping clients organise their thoughts. For therapists, written communication allows therapists time to craft thoughtful, intentional responses that supplement the online CBT materials, ensuring the highest quality of care. For organizations, this method can reduce costs, as it generally takes less time to provide written support that supplements online materials. Additionally, written records of therapeutic exchanges support quality assurance efforts and oversight. Despite these benefits, challenges exist. Some clients may struggle with knowing what to write. For therapists, adapting face-to-face therapeutic communication to this format can be difficult with therapists at first tending to write long emails that duplicate online materials and struggling when they cannot use nonverbal communication. Organizations may also face uncertainty regarding best practices as this method of care represents a significant shift from in-person therapy.

Despite the growing prevalence of written communication in internet-delivered therapy, there has been relatively little attention given to this evolving role of therapists in this space. This presentation will highlight the importance of written communication as a cornerstone of the therapeutic process in ICBT and advocate for its recognition as an evolving role that requires further attention. Findings from studies conducted in a routine ICBT clinic that has now served over 14,000 clients using this approach will be shared. These studies examined desirable and undesirable therapist behaviours in written communication as well as optimal frequency of written therapist support. Results of the research suggest that therapist written behaviours generally fall in the following categories, clarifying procedures, providing support, offering therapeutic insight and guiding clients in making changes. Undesirable behaviours, although uncommon, typically involve failing to respond to or inadequately responding to client concerns. Research further suggests providing written therapeutic support once per week is sufficient, with no added benefits obtained with offering one-business-day or twice weekly support. Additionally, client reflection questionnaires have shown themselves to be useful for facilitating this mode of delivery. Audit and feedback have proven beneficial for improving therapist behaviours over time. While the presentation will focus on therapist-guided ICBT, observations regarding therapeutic written communication are expected to be relevant to other e-mental health interventions. Finally, future directions in this area will be highlighted, with particular emphasis on the role of artificial intelligence in assisting with written communication. As the digital health landscape evolves, recognizing and refining the role of written therapeutic communication is essential.