Treatment outcomes of Sooma Depression Treatment

During last few years, transcranial direct current stimulation (tDCS) has become a treatment option for major depressive disorder. The Royal College of Psychiatrists gave out a statement about the subject in February 2017 and the latest meta-analysis concluded tDCS to be as effective as rTMS and antidepressant pharmaceuticals in primary care. Now, we’d like to ask 10 minutes of your time as we go through real-world treatment outcomes of Sooma Depression Therapy.

Here is a snapshot of what follows:

  • Treatment outcomes from 227 patients administered with Sooma Depression Therapy either as an add-on treatment or as monotherapy.

  • Patients visited an outpatient clinic to receive the treatment, or self-administered it at home. 59% of patients achieved treatment response and 18% complete remission.

  • The mean improvement was 49% after two or three weeks of treatment.

  • The treatment was well tolerated. No serious adverse events occurred during 2839 treatment sessions.

You may also download this article as a PDF. Supplementary materials are only available online.

Outcomes of Sooma Depression Therapy


Sooma Depression Therapy uses transcranial direct current stimulation (tDCS) to modulate brain activity of the areas affected by depression. It is an effective and well-tolerated treatment option for patients with depression. Sooma Depression Therapy can be prescribed as a monotherapy, or it can be added to pharmaceutical or psychosocial treatment options.

Ten clinics worldwide have provided treatment outcomes from patients administered with Sooma Depression Therapy. The outcome data reflect how the treatment is applied in clinical practice today. Moreover, it shows what can be realistically expected as a treatment outcome. The data includes both unipolar and bipolar patients.

Sooma Depression Therapy

Figure 1: Sooma Depression Therapy. The Sooma tDCS medical device consists of a small, battery-powered stimulator, electrodes with conductive medium, and a head cap ensuring correct electrode positioning. Each session delivers a constant current of 2mA for 30 minutes, which is repeated each weekday for 2 to 3 weeks. After the acute treatment phase, the sessions can be continued once a week for up to 6 months for maintenance.


Outcome data from a total of 227 patients was provided by ten clinics worldwide. 191 patients completed the treatment (105 females) and were included in the analysis. 36 patients were excluded from the analysis. Reasons for exclusion were: lack of effect (11), missing data in patient forms (11), patient’s own request (4), no ongoing depressive episode (2), treatment of other medical conditions (2), too many missed treatment sessions (2), unreported reasons (3), and side-effects (1). Patient ages ranged from 18 to 80 years old. The majority of patients received the treatment as an add-on (140 patients) while undergoing simultaneous pharmaceutical and/or psychosocial intervention. Of the 140 patients with simultaneous treatments, 127 had at least one antidepressant medication. 51 patients had no other ongoing therapies and 64 had no antidepressant medication.

Five of the reporting clinics represent university hospitals, three are municipality level primary mental healthcare establishments and two offered the treatment as private service providers. The clinics used their preferred depression scale when reporting baseline and end-point data. Treatment response was defined as a 50% decrease in the depression score, while partial treatment response was defined as a 25% decrease in depression score. Remission was defined by the grading guideline of each depression scale.

All patients were treated using the standard Sooma Depression Therapy protocol shown in Figure 1. Each patient received stimulation sessions with Sooma tDCS: 2mA current amplitude, 30-minute session duration, electrode size 35cm2, and bifrontal electrode positioning (anode and cathode on F3 and F4, respectively). Clinicians were allowed to adjust the number of treatment sessions according to patient need. There was no control group.


The treatment course was completed by 191 patients (105 females). 36 patients (16%) dropped out before the end of treatment.

Twelve patients dropped out for lack of perceived effect, two patients were referred to ECT and two patients missed too many sessions. Two patients wanted to discontinue after feeling more anxiety, one due to worsening symptoms and one patient after an undefined side effect. There was no dropout reason given for three patients. Sixty-two patients received an acute treatment of two weeks (10 sessions) while 129 patients were administered with three-week treatment (15 sessions). Three patients had their planned two-week treatment extended to three weeks to improve response. After the acute treatment, 0-10 maintenance sessions were administered in weekly or bi-weekly basis. On average, patients received 15.1 treatment sessions in total. Overview of the patient demographics is shown in Table 1.

Table 1. Patient demographics

Table 1. Patient demographics.

The majority of patients experienced a marked improvement as a result of Sooma Depression Therapy. 113 patients (59% of all patients) responded to the treatment, while 165 patients (86 %) had a partial response. In total, 34 patients (18 %) achieved complete remission.

The mean improvement in depression score was 49%. Seventeen patients improved by more than 75% whereas the score increased for nine patients. For the majority of patients, depression score improvement was between 50% and 75% as shown in Figure 2.

Depression score reduction after Sooma Depression Therapy

Figure 2. Depression score reduction after Sooma Depression Treatment.

The depression was severe for most patients before treatment (53%). Seventy-seven of the patients had moderate depression (40%) and twelve patients were suffering from mild depression (7%). After two or three-week treatment 79% of the patients had either mild depression or were in remission. Twenty-five patients (13%) had moderate depression post-treatment, sixteen of who started with severe depression and nine with moderate. One patient started with moderate depression but ended with severe depression. Fourteen patients had severe depression in both baseline and post-treatment assessment.  Figure 3 shows the depression severity of the patients before and after treatment.

Depression severity before and after treatment

Figure 3. Depression severity before and after treatment. On average, patients had severe depression when starting the treatment and ended up with mild depression after completion of treatment.

127 of the patients (66%) had simultaneous antidepressant medication. Fifty-four were treated with SSRI-class medication, while fifty-one had SNRI-class antidepressant. On average, these patients had 1,5 ongoing antidepressant pharmaceuticals.

Interestingly, patients without simultaneous antidepressant medication improved more (Mean improvement 59%) than patients with medication (43%). There was no difference between patients on SNRI and SSRI medications. The dropout rate was similar between patients with and without antidepressant medication.

Forty-one patients (21%) had antipsychotic pharmaceuticals during Sooma Depression Therapy. Notably, use of antipsychotic medication increased the dropout rate from 16% to 29%.

Moreover, patients with antipsychotic medication had lower symptom improvement (Mean improvement 38%) than patients not taking such medication (50%)

Use of benzodiazepines also increased the likelihood of discontinuing the treatment. The dropout rate was 37% for patients with benzodiazepines and 15% for patients without. A dropout rate of 25 % was seen for patients taking Zopiclone. The change in dropout rate is visualized in Figure 5.

Nineteen patients had ongoing benzodiazepine medication and 8 were treated with Zopiclone. Use of benzodiazepines did not affect response rate.

Dropout rate

Figure 4. The dropout rate in several patient subsets. Use of antipsychotics, benzodiazepines and Zopiclone significantly increased the dropout rate.

Patient perspective

Beyond the change in depression score, patients and nurses were encouraged to describe the experienced effects. Decreased anxiety was the most commonly described effect aside from mood improvement. Several patients reported increased activity and better functionality in daily life. Normalised appetite and sleep patterns were also among the effects reported.  Notably, positive self-experienced symptom improvements did not always correlate with significant improvement in depression score. Figures 5 and 6 show two descriptions of treatment effects.

Figure 5. Testimonial by a patient

Figure 6. Comment from a psychotherapist

Safety and adverse effects

Sooma Depression Therapy is safe and was well-tolerated by patients. The 191 patients who completed the treatment received 2879 treatment sessions and over 1400 hours of stimulation in total. Most common side effects were itching sensations under the electrode during treatment session (58 % of patients reported at least one itching occurrence during treatment phase) and transient headache (27 %). The dropout rate was 16%. One patient discontinued the treatment after expressing a side effect. Two cases of mania or hypomania were reported, but they did not result in discontinuation of treatment nor did they require any kind of medical intervention.


Based on 227 patients reported by ten different clinics, Sooma Depression Therapy is a safe and effective treatment for patients suffering from major depressive disorder. The treatment is well tolerated and can be effectively administered either as monotherapy or as add-on treatment. Moreover, there were no technical issues in administering Sooma Depression Therapy in clinical routine use.

  • Safe and effective

  • Well tolerated by the patients

  • Easy to administer

  • Suitable for clinical routine

How to get started

Sooma Depression Therapy system is portable and does not require fixed installation or specialised facilities. The treatment session can be administered by a trained nurse in a clinic, or by the patient in a home environment. The treatment is easy to combine with psychotherapy or group therapy. Preparations take only a few minutes and the patient is free to engage in normal activities during the session. Sooma will train you and your staff in the use of the system and in how to deliver further training to your patients.

Supplementary materials
Individual patient data

Table 2. Individual patient demographics. Download full table.

Severity scores

Table 3. Scores used to categorize depression severity for each scale