Mechanistic pathways of change in twice weekly versus once weekly sessions of psychotherapy for depression

Long-term outcomes of once weekly v. twice weekly sessions of cognitive behavioral therapy and interpersonal psychotherapy for depression

BACKGROUND

Twice weekly sessions of cognitive behavioral therapy (CBT) and interpersonal psychotherapy (IPT) for major depressive disorder (MDD) lead to less drop-out and quicker and better response compared to once weekly sessions at posttreatment, but it is unclear whether these effects hold over the long run.

AIMS

Compare the effects of twice weekly v. weekly sessions of CBT and IPT for depression up to 24 months since the start of treatment.

METHODS

Using a 2 × 2 factorial design, this multicentre study randomized 200 adults with MDD to once or twice weekly sessions of CBT or IPT over 16-24 weeks, up to a maximum of 20 sessions. Main outcome measures were depression severity, measured with the Beck Depression Inventory-II and the Longitudinal Interval Follow-up Evaluation. Intention-to-treat analyses were conducted.

RESULTS

Compared with patients who received once weekly sessions, patients who received twice weekly sessions showed a significant decrease in depressive symptoms up through month 9, but this effect was no longer apparent at month 24. Patients who received CBT showed a significantly larger decrease in depressive symptoms up to month 24 compared to patients who received IPT, but the between-group effect size at month 24 was small. No differential effects between session frequencies or treatment modalities were found in response or relapse rates.

CONCLUSIONS

Although a higher session frequency leads to better outcomes in the acute phase of treatment, the difference in depression severity dissipated over time and there was no significant difference in relapse.

Measuring the active elements of cognitive-behavioral therapies

Understanding how and for whom cognitive-behavioral therapies work is central to the development and improvement of mental health interventions. Suboptimal quantification of the active elements of cognitive-behavioral therapies has hampered progress in elucidating mechanisms of change. To advance process research on cognitive-behavioral therapies, we describe a theoretical measurement framework that focuses on the delivery, receipt, and application of the active elements of these interventions. We then provide recommendations for measuring the active elements of cognitive-behavioral therapies aligned with this framework. Finally, to support measurement harmonization and improve study comparability, we propose the development of a publicly available repository of assessment tools: the Active Elements of Cognitive-Behavioral Therapies Measurement Kit.

G-FORCE: the effectiveness of group psychotherapy for Cluster-C personality disorders: protocol of a pragmatic RCT comparing psychodynamic and two forms of schema group therapy

BACKGROUND

Cluster-C personality disorders (PDs), characterized by a high level of fear and anxiety, are related to high levels of distress, societal dysfunctioning and chronicity of various mental health disorders. Evidence for the optimal treatment is extremely scarce. Nevertheless, the need to treat these patients is eminent. In clinical practice, group therapy is one of the frequently offered approaches, with two important frameworks: schema therapy and psychodynamic therapy. These two frameworks suggest different mechanisms of change, but until now, this has not yet been explored. The purpose of the present G-FORCE trial is to find evidence on the differential (cost)effectiveness of two forms of schema group therapy and psychodynamic group therapy in the routine clinical setting of an outpatient clinic and to investigate the underlying working mechanisms and predictors of outcome of these therapies.

METHODS

In this mono-centre pragmatic randomized clinical trial, 290 patients with Cluster-C PDs or other specified PD with predominantly Cluster-C traits, will be randomized to one of three treatment conditions: group schema therapy for Cluster-C (GST-C, 1 year), schema-focused group therapy (SFGT, 1.5 year) or psychodynamic group therapy (PG, 2 years). Randomization will be pre-stratified on the type of PD. Change in severity of PD (APD-IV) over 24 months will be the primary outcome measure. Secondary outcome measures are personality functioning, psychiatric symptoms and quality of life. Potential predictors and mediators are selected and measured repeatedly. Also, a cost-effectiveness study will be performed, primarily based on a societal perspective, using both clinical effects and quality-adjusted life years. The time-points of assessment are at baseline, start of treatment and after 1, 3, 6, 9, 12, 18, 24 and 36 months.

DISCUSSION

This study is designed to evaluate the effectiveness and cost-effectiveness of three formats of group psychotherapy for Cluster-C PDs. Additionally, predictors, procedure and process variables are analysed to investigate the working mechanisms of the therapies. This is the first large RCT on group therapy for Cluster-C PDs and will contribute improving the care of this neglected patient group. The absence of a control group can be considered as a limitation.

TRIAL REGISTRATION

CCMO, NL72826.029.20 . Registered on 31 August 2020, first participant included on 18 October 2020.

Individual psychotherapy for cluster-C personality disorders: protocol of a pragmatic RCT comparing short-term psychodynamic supportive psychotherapy, affect phobia therapy and schema therapy (I-FORCE)

BACKGROUND

Cluster-C personality disorders (PDs) are highly prevalent in clinical practice and are associated with unfavourable outcome and chronicity of all common mental health disorders (e.g. depression and anxiety disorders). Although several forms of individual psychotherapy are commonly offered in clinical practice for this population, evidence for differential effectiveness of different forms of psychotherapy is lacking. Also, very little is known about the underlying working mechanisms of these psychotherapies. Finding evidence on the differential (cost)-effectiveness for this group of patients and the working mechanisms of change is important to improve the quality of care for this vulnerable group of patients.

OBJECTIVE

In this study, we will compare the differential (cost)-effectiveness of three individual psychotherapies: short-term psychodynamic supportive psychotherapy (SPSP), affect phobia therapy (APT) and schema therapy (ST). Although these psychotherapies are commonly used in clinical practice, evidence for the Cluster-C PDs is limited. Additionally, we will investigate predictive factors, non-specific and therapy-specific mediators.

METHODS

This is a mono-centre randomized clinical trial with three parallel groups: (1) SPSP, (2) APT, (3) ST. Randomization on patient level will be pre-stratified according to type of PD. The total study population to be included consists of 264 patients with Cluster-C PDs or other specified PD with mainly Cluster-C traits, aged 18-65 years, seeking treatment at NPI, a Dutch mental health care institute specialized in PDs. SPSP, APT and ST (50 sessions per treatment) are offered twice a week in sessions of 50 min for the first 4 to 5 months. After that, session frequency decreases to once a week. All treatments have a maximum duration of 1 year. Change in the severity of the PD (ADP-IV) will be the primary outcome measure. Secondary outcome measures are personality functioning, psychiatric symptoms and quality of life. Several potential mediators, predictors and moderators of outcome are also assessed. The effectiveness study is complemented with a cost-effectiveness/utility study, using both clinical effects and quality-adjusted life-years, and primarily based on a societal approach. Assessments will take place at baseline, start of treatment and at 1, 3, 6, 9, 12, 18, 24 and 36 months.

DISCUSSION

This is the first study comparing psychodynamic treatment to schema therapy for Cluster-C PDs. The naturalistic design enhances the clinical validity of the outcome. A limitation is the lack of a control group for ethical reasons.

TRIAL REGISTRATION

NL72823.029.20 [Registry ID: CCMO]. Registered on 31 August 2020. First participant included on 23 October 2020.