Multimodal Biomarkers of Electroconvulsive Therapy in Severe and Treatment-resistant Depression

Electroconvulsive therapy (ECT) is a widespread and safe stimulation method that has been used successfully for decades in psychiatric diseases such as severe or therapy-resistant depression. Unfortunately, ECT still has stigmas attached to it. The latter often leads to reservations among those affected and perturbs optimal and guideline-based therapy. Despite the demonstrated effectiveness of ECT, prediction of treatment response is still not possible. This is due to the limited knowledge about the biological mechanisms of action of ECT, especially on an individuum level. Thus, the DetECT study intends to recruit 134 inpatient subjects of the Max Planck Institute of Psychiatry with severe and/or treatment resistant depression receiving ECT to perform weekly psychometry and blood draws before and after ECT sessions one, seven, and twelve. The subsequent biopsychological analysis comprises omics, physiological, neurocognitive, and psychometric measurements. The multimodal data collected will be used to identify data-driven clusters associated with ECT mechanisms and outcome.

Background: With around 320 million cases, depression is one of the most common psychiatric disorders worldwide. In addition to psychopharmacological treatment and psychotherapy, ECT is a common treatment option. This technique is referred to as the gold standard of stimulation procedures due to its good effectiveness and safe application. Despite the widespread use of ECT, knowledge of the underlying biological processes that lead to symptom improvement is still limited. Accordingly, there are no clinical-psychological or biological biomarkers that can reliably predict the course of the disease or the response to ECT in individual cases. Due these circumstances, the primary aim of the present DetECT study is to identify individual parameters or clusters of biological and psychological-clinical features that are associated with the course of depression under ECT. Material and Methods: The monocentric, explorative-prospective DetECT study (planned total duration: 3 years) recruits adult and legally competent patients who receive inpatient treatment at the Max Planck Institute for Psychiatry and undergo ECT for a severe depressive episode. Participants will have a total of five (in select cases: seven) venous blood samples taken over an average of seven weeks, that is parallel to the first twelve ECT session on three treatment days (total volume: \~124 ml; in select cases 152 ml). All participants will also be asked to complete self-rating questionnaires on their depressive and neurocognitive symptoms (Patient Health Questionnaire 9 and 15, Questionnaire on Mental Capacity, Beck Depression Inventory II) each week. At the beginning, in the middle and at the end of the seven-week study period, three external assessment questionnaires (Montgomery-Åsberg Depression Rating Scale, Hamilton Rating Scale for Depression, Global Assessment of Functioning) are collected by the study staff. In addition, medical, anamnestic and sociodemographic information on the course of illness and therapy is extracted from the patient records. All biomaterials and data collected in the DetECT study, together with the samples and data from the Max Planck of Psychiatry's biobanking, are double pseudonymised or anonymised and stored for 10 or 30 years, depending on subject preference. Protecting the privacy and rights of the study participants is our top priority. All analyses are performed only by using the participant's study code to guarantee a maximum of data security. Modern and multidimensional analysis techniques will be employed to the biopsychological parameters and to the clinical and socioeconomic information. On a group or subgroup level, this will likely help to link multidimensional biomarker clusters with treatment outcome under ECT. Discussion: Taken together, the DetECT study aims to improve the quality of psychiatric treatment of severely depressed patients. The investigators argue that the study novelty lies in its longitudinal and multimodal data collection and analysis approach. This could effectively advance personalization and specification of ECT indication and application. Ultimately as well as in a nutshell, the overall study objective is to identify those patients who benefit most from in terms of the effect/side-effect profile.