The impact of treatment resistance on outcome and course of electroconvulsive therapy in major depressive disorder.

INTRODUCTION: Major depressive disorder (MDD) is a common psychiatric disorder. Despite several treatment options, a subgroup of patients will not respond to the commonly used antidepressant treatments and thus express treatment resistance (TRD). TRD can be quantified with the Dutch Measure for Treatment Resistance in Depression (DM-TRD). Electroconvulsive therapy (ECT) is an effective treatment for MDD, also in TRD. Yet, the position of ECT as "treatment-of-last-resort" may decrease the likelihood of beneficial outcome. Our aim was to investigate the association between treatment resistance and outcome and course of ECT. METHODS: We performed a retrospective, multicenter cohort study with 440 patients of which data was retrieved from patient records as collected in the Dutch ECT Cohort database. Linear and logistic regression models were used to explore the association between level of treatment resistance and outcome of ECT. Median split was used to explore the differences between high and low level of TRD and course of treatment. RESULTS: A higher DM-TRD score was associated with significantly smaller reduction of depression symptoms (R2 = 0.160; ß = -2.968; p < 0.001) and lower chance of response (OR = 0.821 [95 CI: 0.760-0.888]; ß = -0.197; p < 0.001). Low level TRD patients underwent fewer ECT sessions (mean 13 ± 6 SD vs. 16 ± 7 SD; p < 0.001) and fewer switches from right unilateral tot bifrontotemporal electrode placement (29% vs. 40%; p = 0.032). CONCLUSION: Reserving ECT as "treatment-of-last-resort" in the treatment algorithm for MDD seems questionable, because in our study lower level of treatment resistance predicted more beneficial ECT-outcome. Moreover, providing ECT in less treatment resistant patients showed fewer needed ECT-sessions and less switches to BL electrode placement, which may decrease the risk for cognitive side-effects.

Transdiagnostic psychiatry: Symptom profiles and their direct and indirect relationship with well-being.

BACKGROUND: Heterogeneity and comorbidity in psychiatric disorders are common, however, little is known about the impact on well-being and the role of functional limitations. We aimed to identify transdiagnostic psychiatric symptom profiles and to study their association with well-being and the mediating role of functional limitations in a naturalistic psychiatric patient group. METHODS: We used four disorder-specific questionnaires to assess symptom severity within a sample of 448 psychiatric patients with stress-related and/or neurodevelopmental disorders and 101 healthy controls. Using both exploratory and confirmatory factor analyses we identified transdiagnostic symptom profiles, which we entered into a linear regression analysis to assess their association with well-being and the mediating role of functional limitations in this association. RESULTS: We identified eight transdiagnostic symptom profiles, covering mood, self-image, anxiety, agitation, empathy, non-social interest, hyperactivity and cognitive focus. Mood and self-image showed the strongest association with well-being in both patients and controls, while self-image also showed the highest transdiagnostic value. Functional limitations were significantly associated with well-being and fully mediated the relationship between cognitive focus and well-being. LIMITATIONS: The participant sample consisted of a naturalistic group of out-patients. While this strengthens the ecological validity and transdiagnostic perspective of this study, the patients with a single neurodevelopmental disorder were underrepresented. CONCLUSION: Transdiagnostic symptom profiles are valuable in understanding what reduces well-being in psychiatric populations, thereby opening new avenues for functionally meaningful interventions.

Negative memory bias as a transdiagnostic cognitive marker for depression symptom severity.

BACKGROUND: Negative memory bias is a strong risk factor for the development and maintenance of depression. Recent evidence also found negative memory bias in other mental disorders. Here, we aim to: 1) assess the presence and strength of negative memory bias in a range of (comorbid) mental disorders, 2) investigate which disorder-specific symptoms are associated with negative memory bias, and 3) test whether negative memory bias might be a transdiagnostic mechanism. METHODS: Negative memory bias was measured in patients with at least one diagnosis of a stress-related disorder (n = 86), a neurodevelopmental disorder (n = 53), or both (n = 68), and 51 controls. Depression, anxiety, attention-deficit/hyperactivity disorder, and autism spectrum disorder symptom severity was assessed using questionnaires. Groups were compared on negative memory bias and the associations between negative memory bias and symptom severity were made using linear regression models. RESULTS: All patient groups showed stronger negative memory bias than the controls. Negative memory bias was individually associated with all symptom severity indices, but when added into a single model, only the association with depressive symptom severity remained. This persisted after controlling for diagnostic group. LIMITATIONS: Due to the cross-sectional sectional study design, we could only look at the associations between negative memory bias and disorder-specific symptoms and not at the direction of the effects. CONCLUSIONS: Negative memory bias is characteristic of a depressotypic processing style and present in different mental disorders. It might play a mechanistic role in the development of (subclinical) co-occurrence between mental disorders.

A randomized controlled trial of a standard 4-week protocol of repetitive transcranial magnetic stimulation in severe treatment resistant depression.

BACKGROUND: Treatment options for major depressive disorder (MDD) in individuals who are depressed for at least 2 years and failed two or more different types of therapeutic intervention, remain scarce. Being less invasive than electroconvulsive therapy, repetitive transcranial magnetic stimulation (rTMS) might be an alternative treatment option. RESEARCH QUESTION: Does high frequency rTMS applied over the left prefrontal cortex ameliorate depressive symptoms in patients with treatment resistant major depressive disorder and is the efficacy dependent on treatment resistance? METHOD: We performed a randomized controlled trial investigating the effect of twenty sessions of real or sham-rTMS, during 4 consecutive weeks. Efficacy was blindly rated with the Hamilton depression rating scale (HDRS-17) at baseline and 1 week after end of treatment, and the Dutch method for quantification of treatment resistance in Depression (DM-TRD) was assessed at baseline. RESULTS: An interim analysis showed no differences in antidepressant response between real and sham rTMS and we therefore discontinued the RCT after 31 patients. The mean difference of the HDRS score between baseline and post-treatment was 3.7 (± 4.0; change 16%), indicating a small but significant improvement across time (F(1,30)=25.4;p < 0.01). There were no differences however between the treatment arms (F(1.30) = 1.5;p = 0.23). We did find a negative correlation between the change in HDRS score and DM-TRD in the active rTMS group, but this correlation was not significantly different from the sham group. CONCLUSION: "Standard" 4-week rTMS treatment is not effective in chronic, severe treatment-resistant depressed patients. While a replication of our data in this patient group may be ethically difficult, further research with less treatment resistant patients might help in positioning rTMS within the current stepped care approach to depression.