The study will apply state of the art radiology through advanced magnetic resonance imaging (MRI) techniques to investigate structural and functional brain effects of electroconvulsive therapy (ECT) and repetitive transcranial magnetic stimulation (rTMS).

As a multi-disciplinary collaboration, imaging findings will be correlated to psychiatric response parameters, neuropsychological functioning as well as neurochemical and genetic biomarkers that can elucidate the underlying mechanisms. The aim is to document both treatment effects and potential harmful effects of ECT and TMS

Sample, three groups:

ECT: n = 50 patients in a major depressive episode (bipolar and major depressive disorder) who have accepted treatment with ECT.

TMS: n = 50 patients in a major depressive episode (bipolar and major depressive disorder) who have accepted treatment with TMS.

HC: = 50 age and gender matched healthy volunteers not receiving ECT nor TMS.

Observation time: six months, with the time points as specified below. ECT is typically given three times weekly, but exceptions may occur. Hence, time points are specified as the number of ECT treatments given rather than an exact number of days which will vary.

Tp1: 2 hours before the first treatment session (day 1, baseline), Tp2: 2 hours after the first treatment session (day 1), Tp3: before the 7th ECT session and corresponding time point for TMS (~ day 15), Tp4: 1-2 weeks after last treatment session (~ day 30 - 50), Tp5: 6 months after treatment (~ day 180),

Healthy controls are only assessed at Tp1,2,4,5

Inclusion Criteria:

ECT:

• Patients (>18) referred to the center of ECT and accepted for treatment
• because of moderate and severe depression
• fulfilling the criteria for the following ICD-10 diagnosis: F 31.3 and F31.4; F32.1 and F32.2 and F32.3; F33.1 and F33.2 and F33.3.
• In addition, the symptom intensity must be verified by a MADRS score ≥ 25.
• There is no upper age for participation, however, the responsible clinician will consider if patients are eligible for inclusion (functioning, enabled to give informed consent).

TMS:

• Patients (>18) referred to the center of TMS and accepted for treatment
• because of moderate and severe depression
• fulfilling the criteria for the following ICD-10 diagnosis: F 31.3 and F31.4; F32.1 and F32.2 and F32.3; F33.1 and F33.2 and F33.3.
• In addition, the symptom intensity must be verified by a MADRS score ≥ 25.
• There is no upper age for participation, however, the responsible clinician will consider if patients are eligible for inclusion (functioning, enabled to give informed consent).

Healthy controls:

• Age and gender matched (to the patient groups).
• No history of psychiatric illness and no current depression.
• No contraindication for MRI scanning.

Exclusion Criteria:

• ECT / TMS treatment within the last 12 months.
• Patients unable to give informed consent (according to the responsible clinician or ECT / TMS responsible).
• Patients who cannot participate in the MR scanning

Patients accepted for ECT or TMS at Haukeland University Hospital will be included.

Control groups: Healthy controls undergoing the same investigations as the ECT and TMS patient groups, but not receiving any treatment