The Cerebral and Cognitive Changes After Intermittent Theta Burst Stimulation (iTBS) Treatment for Depression

The Cerebral and Cognitive Changes After Intermittent Theta Burst Stimulation (iTBS) Treatment for Depression A Randomised Double-blind Sham-controlled Trial

The present project aims to assess the neurocognitive impact of a two-week once-a-day regimen of intermittent theta burst stimulation (iTBS) compared to sham iTBS, when targeting the left dorsolateral prefrontal cortex (LDLPFC) in clinically depressed outpatients. The study investigates the relationships between changes in cerebral measures and cognitive performance on an N-back task in relation to the antidepressive effect following iTBS.

The study is a randomized sham controlled double blind clinical trial in which the changes in cortical functions associated with the anti-depressive effect of two weeks of once-a-day neuronavigated iTBS over the left dorsolateral prefrontal cortex (LDLPFC) will be investigated in comparison to sham iTBS. Participants will be recruited prospectively, and the study is performed at a single university hospital. After written informed consent is obtained from eligible, volunteering patients, baseline measurements will be administrated, and the patient will be allocated to either sham or active iTBS once a day for 10 consecutive workdays. A total of three measurements will take place, namely at baseline prior to iTBS treatment, after two weeks with iTBS treatment (posttest) and four weeks after (follow-up). The primary outcome measures will be assessed from baseline to the posttest.

Inclusion criteria:

• Patients must meet the diagnostic criteria of at least a moderate depression
• The duration of the current depressive episode must have lasted more than 2 weeks but less than 2 years
• Drug therapy must have been stable for the last three weeks prior to the first treatment day with iTBS
• Patients must volunteer to provide informed consent, be able to follow the treatment schedule and have a satisfactory safety screening for iTBS and MRI

Exclusion criteria:

• The current depressive episode is in the mild range
• The current episode fulfills the criteria for a major depressive episode requiring inpatient treatment and/or electroconvulsive therapy,
• The current depressive episode is clearly triggered by grief or a recent major stressful life event
• Bipolar disorder
• Borderline personality disorder
• Psychotic symptoms
• Alcohol or substance abuse/addiction in the last 6 months
• Current eating disorders
• Obsessive- compulsive disorders
• Post-traumatic stress disorder
• A life-time medical history of seizure
• Neurological or neurosurgical pathologies
• Cardiac or systemic disease
• Metallic prosthetic material or foreign objects (pacemakers, prosthetic eye equipment, etc.)
• Autism
• Pregnancy
• Currently using of antipsychotic medication or benzodiazepines - or any medication that interferes with motor threshold excitability