۱- Introduction

۲- Material and methods

۳- Results

۴- Discussion

۵- Conclusions

References

Abstract

Internet-based cognitive behavior therapy (ICBT) has proved effective in reducing mild to moderate depressive symptoms. However, only a few studies have been conducted in a regular healthcare setting which limits the generalizability of the results. The influence of psychiatric comorbidity on outcome is not well understood. In the current study, patients with mild to moderate depressive symptoms in primary and psychiatric care were interviewed using the SCID-I and SCID-II to assess psychiatric diagnoses. Those included were randomly allocated to ICBT (n = 48) or to an active control condition (n = 47). Both groups received therapist support. At post-treatment, ICBT had reduced depressive symptoms on the BDI-II more than the active control intervention (p = .021). However, the difference between groups was no longer significant at the 6-, 12- or 24-month follow-ups. The within-group effect size after ICBT (BDI-II) was large (d = 1.4). A comorbid anxiety disorder didn’t moderate the outcome, while the presence of a personality disorder predicted significantly less improvement in depressive symptoms. ICBT had a large effect on depressive symptoms in a sample from regular healthcare. It is possible to obtain a large effect from ICBT despite comorbid anxiety, however, including patients with a comorbid personality disorder in the current form of ICBT seems questionable.

Introduction

It has been found that cognitive behavioral therapy (CBT) is transferable to Internet format, especially when guided by a therapist (Andersson, 2016) who provides support, encouragement, and occasionally direct therapeutic activities (Johansson and Andersson, 2012). Meta-analyses show that guided Internet-based CBT (ICBT) is an effective treatment for depression (Karyotaki et al., 2018; Richards and Richardson, 2012). ICBT with guidance seems to be equally effective as face-to-face therapy (Andersson et al., 2016), and offering ICBT as a complement to standard care expands the availability of effective psychological treatment, as it enables therapists to increase their case load. There are clear indications that guided internet-based psychological treatments are more effective than unguided treatments (Richards and Richardson, 2012), although there are exceptions (Titov et al., 2014). The guidance is typically supportive in nature, including encouragement and reinforcement (Holländare et al., 2016; Paxling et al., 2013; Sanchez-Ortiz et al., 2011) but how different aspects of guidance influence outcome is still not fully understood. Most studies on internet-based psychological treatment have investigated CBT-based interventions, (Ruwaard et al., 2009; Andersson et al., 2005; Hedman et al., 2014; Ruwaard et al., 2012; Williams and Andrews, 2013; Hedman et al., 2012; Dear et al., 2018; Titov et al., 2016; Johansson et al., 2019; Mathiasen et al., 2018) although one study compared internet-based psychodynamic treatment for depression with an active control condition with positive results (Johansson et al., 2013). One study compared guided ICBT with individualized email therapy (Vernmark et al., 2010), and moderate to large effect sizes were found in both groups.