Introduction:

Adjustment disorder (AjD) is a maladaptive response to one or more psychosocial stressors. In many cases, the symptomatology of this disorder disappears once the stressor or its consequences are no longer present. However, in some cases, if left untreated, the symptoms may worsen and develop into a more severe mental disorder. In this regard, different authors propose that a low-intensity intervention may be suitable for this disorder. Previous studies with other mental disorders and with patients with AjD found that blended interventions can be a viable and effective option. The aim of this study is to analyze the feasibility (the participants' expectations and preferences, the satisfaction and acceptance, the appropriateness of different methods of recruitment and data collection, and the reasons for dropping out) of a blended cognitive-behavioral intervention (CBT) for AjD that combines the use of a self-applied Internet-based program with videoconference sessions with a therapist. As a secondary objective, the potential efficacy of this intervention will be tested. Method and

analysis:

A feasibility trial with a single-group and open-trial design will be conducted. A total of 41 participants will be assigned to the single treatment group. All the participants will be assessed for eligibility and respond at four measurement points pre-treatment, post-treatment, and 3- and 12-month follow-ups. The treatment combines the use of an Internet-based intervention through a web platform with videoconference sessions with a therapist every 10-12 days. The intervention contains seven modules and is based on CBT. The main outcome measures are related to the feasibility of the intervention (adherence, treatment satisfaction and expectations, participants' opinions, preferences, therapeutic alliance, and usability). Clinical measures will also be assessed.

Discussion:

To the best of our knowledge, this is the first study to test a blended intervention for AjD in the Spanish language. We expect this intervention to be feasible, and that a future Randomized Controlled Trial will be able to show its efficacy. Potential limitations include difficulties in recruiting the sample, failures in the computer systems, or a high dropout rate. Measures have been taken to try to reduce the impact of these limitations. This study received the approval of the Ethics committee of Universitat Jaume I in March 2022 (CD/42/2022). Trial registration ClinicalTrials.gov Identifier NCT05464121. Registered 19 July 2022, https//clinicaltrials.gov/ct2/show/NCT05464121.