Anodal Stimulation tDCS, Major Depression, Cognitive Control, Emotion Regulation
Conditions
Brief summary
Deficient cognitive control (CC) and the use of dysfunctional emotion regulation strategies (ERS) are both central characteristics of major depression. Both are associated with reduced activity of the dorsolateral prefrontal cortex (dlPFC). Transcranial direct current stimulation (tDCS) is a safe, simple and effective non-invasive method to modulate the cortical excitability. The goal of this randomized, sham-controlled, double blind clinical trial is to examine the effect of transcranial direct current stimulation (tDCS) on the CC and ERS in depressed patients compared to healthy subjects. Overall, the study will include 44 participants (22 depressed Patients and 22 healthy subjects). Each participant will complete a CC task while receiving sham tDCS in one session and anodal tDCS in the other session (counterbalanced). Afterwards the ERS 'rumination' will be measured during a resting phase by means of a questionnaire and psychophysiological measures (heart rate variability). The investigators hypothesize (a) an amelioration of CC by anodal tDCS and (b) a reduced use of the dysfunctional emotion regulation strategy 'rumination' after anodal tDCS. Overall this experiment will provide new and reliable data for the development of new treatment methods.
Detailed description
1. Working hypothesis: anodal transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (dlPFC) can enhance healthy and impaired cognitive control (CC) and reduce the use of dysfunctional emotion regulation strategies. 2. Previous work of the investigators: The investigators previous work has provided decisive evidence for polarity-specific activity-dependent effects of tDCS to the left dlPFC on cognitive planning and control of emotional information processing in healthy subjects and patients with MD. Particularly, reduced prefrontal brain activity during a working memory task in patients with MD was found by using near infrared spectroscopy (NIRS). In addition, the investigators demonstrated that a single session, anodal, activity enhancing tDCS to the left dlPFC ameliorates deficient CC in patients with depression, whereas cathodal, activity reducing tDCS, induces a depression-like negativity bias in healthy subjects. Furthermore, the investigators showed that during anodal tDCS of the left dlPFC healthy subjects showed (a) better performance in a CC task (b) no increase in angry mood after the task compared to a control group and (c) that elevated angry mood was associated to a worse performance in the CC task. 3. Aims and workplan: to investigate the effects of anodal tDCS of the left dLPFC in healthy and depressed subjects the investigators will conduct a double-blind, randomized, sham-controlled, cross-over design. In two sessions each participant (22 depressed and 22 healthy subjects, N= 44) will complete a CC task while receiving anodal tDCS (1 mA) to the left dlPFC in one session and sham tDCS in the other session (counterbalanced). Afterwards the ERS 'rumination' will be measured during a resting phase by means of a questionnaire and psychophysiological measures.
Interventions
for the placebo control condition, the transcranial direct current stimulation will only last for 30 seconds and will then be ramped down.
Sponsors
German Federal Ministry of Education and Research
Universität Tübingen
University Hospital Tuebingen
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Caregiver, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
for depressed patients * diagnosed major depression (DSM-V) * stable medication for four weeks Inclusion Criteria for all participants * right handedness
Exclusion criteria
* history of seizures * metal device throughout the body * pregnancy * use of von antipsychotics / mood stabilizer * diagnosed bipolar disorder * current substance abuse (nicotine excluded) * diagnosed psychotic diseases * diagnosed anorexia nervosa * diagnosed personality disorders: cluster A, antisocial personality disorder, borderline personality disorder
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Interstimulusintervall and number of correct trials in the PASAT | Assessment during stimulation/ sham stimulation in two sessions through study completion, on average 10 days. | To measure the performance in the PASAT the number of correct trials as well as the mean Interstimulusintervall will be assessed. |
| Change of positive and negative affect | The positive and negative affect is assessed (a) right before and after the PASAT in two sessions through study completion, on average 10 days. And (b) also after the resting phase in two sessions through study completion, on average 10 days. | Change of positive and negative affect after, compared to before performing the PASAT and also change of the affect during the resting phase. |
| Heart rate variability | in two sessions through study completion, on average 10 days | The Heart Rate Variability will be measured during the resting phase right after the measurement of the affect. |
| Score in state rumination questionnaire | in two sessions through study completion, on average 10 days | The state rumination will be measured after the resting phase |
Countries
Germany
Contacts
Primary ContactChristian Plewnia, MD
Outcome results
None listed