Short summary

With this study, we will investigate whether Schema Therapy (ST) of longer duration (up to 30 sessions) outperforms current treatment as usual (TAU) for a distinct, large group of depression patients for whom the current treatment is often unsatisfactory: patients with chronic and/or treatment resistant depression (CTRD). Further, a more explicit, all-encompassing dimensional definition of CTRD will be developed, which as the first staging model to date will include failed psychotherapy trials.

Rationale

Major depressive disorder has an estimated prevalence in Denmark of 100,000-200,000 patients, whereof 30-35% suffer from CTRD. International studies comparing CTRD with non-chronic depression patients show increased suicidal risk, non-suicidal mortality (e.g. caused by coronary disease; Carney & Freedland, 2009; Pfeiffer et al., 2013), lower quality of life and social, emotional and physical functioning (Jaffe et al., 2019), and doubled risk of hospitalization. Further, costs for health service use is up to 40% higher than for other depression patients (Gibson et al., 2010; Trevino et al., 2014).

Even evidence-based therapies developed particularly for chronic depression, such as cognitive behavioral analysis system of psychotherapy (CBASP) only bring 1/3 of patients to full remission, with no added long-term, prophylactic effect toward relapse compared to treatment with antidepressants (Gelenberg et al., 2003; Keller et al., 2000; Wiersma et al., 2014). This makes it worthwhile to explore new treatment options.

CTRD-patients seem to differ substantially from non-CTRD patients in factors such as adverse events in childhood, higher prevalence of comorbid personality disorders as well as inhibiting personality features, interpersonal behavior, and cognitive styles (Barnhofer, 2014; Jobst et al., 2016; Köhler et al., 2019; Lim & Barlas, 2019; Nelson et al., 2017; Renner et al., 2014; Riso, 2002).

As schema therapy specifically aims to identify and ameliorate early, adverse childhood experiences and unmet basic emotional needs through modifying maladaptive schemas, it is a particularly promising treatment for CTRD which could potentially provide a more enduring effect than other psychotherapeutic treatments. Further, as the societal costs for these patients are substantial, the study will investigate whether individual and more extensive treatment than what is usually given as part of psychiatric treatment is in fact cost-effective in the long term.

Description of the cohort

The included participants are outpatients, aged 18 or above, either already undergoing or referred to treatment for depression in the psychiatric sector. Participating sites are located in the psychiatric outpatient clinics in Odense, Ballerup, Frederiksberg/Copenhagen and Nannasgade/Copenhagen.

Participants have a clinical moderate to severe depression as measured by the SCID-5-CT diagnostic interview (First et al., 2015): duration minimum two years or persistent after ≥ 2 trials of antidepressants from different classes, in an adequate dosage and time period (≥ 4 weeks) or moderate treatment resistance as measured on the MSM-scale, score > 6. Exclusion criteria are alcohol or substance abuse, bipolar or psychotic disorder, acute severe suicidal risk, and mental disability (estimated IQ < 70).

Participants are recruited when first referred to treatment at a participating site.

Data and biological material

The primary outcome will be severity of depression assessed by interview on the Hamilton-6 Rating Scale for Depression (HAMD-6, e.g., Licht et al., 2005; Timmerby et al., 2017), assessed at 12 months after the baseline assessment, i.e. approximately at the end of treatment for the ST group (while TAU will be of varying length). At 6 and 24 months after the baseline assessment, additional data will be collected on the HAMD-6 as secondary outcomes.

Secondary outcomes (same time points as described above):

Level of functioning; Work and Social Adjustment Scale (Mundt et al., 2002).

Well-being; WHO-5 Well-Being Index (Topp et al., 2015).

Recovery; INSPIRE-O Brief (Williams et al., 2012).

Negative effects of treatment; Negative effects Questionnaire (Rozental, 2018).

Patient-defined problem changes; Psychological Outcome Profiles - PSYCHLOPS (Ashworth, 2004).

Reactions to anger; Dimensions of Anger Reactions - Revised (DAR), (Kannis-Dymand et al., 2019).

Anger processing; Metacognitive Anger Processing scale, Short Version (MAP-SV). (Moeller, Juul, & Arendt, 2022).

Repeated, negative thinking; Perseverative Thinking Questionnaire (PTQ) (validation article on a Danish population is in process by some of the researchers in this project (Moeller, S.B; Arendt, I.-M. T. P.).

Depression and anxiety; Symptom Checklist-10 (SCL-10) (Bech, Austin & Lau, 2018).

Health-related quality of life; Euro-Qol-5D (EQ-5D), (Peasgood et al., 2012; Sørensen et al., 2009).

Collaborating researchers and departments

Psykoterapeutisk Ambulatorium, Psykiatrisk Center Ballerup, Region Hovedstadens Psykiatri

• Afsnitsleder Kirsten Stengaard Møller

Psykoterapeutisk Klinik Nannasgade, Psykiatrisk Center København, Region Hovedstadens Psykiatri

• Klinikleder Nicole G. Rosenberg

Psykoterapeutisk Klinik Frederiksberg, Psykiatrisk Center København, Region Hovedstadens Psykiatri

• Afsnitsledende overlæge Sebastian Swane
• Afsnitsledende specialpsykolog Shamaiela Anwar

Psykiatrisk Afdeling Odense - Universitetsfunktion, Region Syddanmark Psykiatri

• Ledende overlæge Susie Andersen