July 25, 2018
When researchers conduct a study on a treatment for depression, how do they determine if the treatment was successful? Patients who struggle with depression may already know that success in treatment isn’t always simple to measure. For that reason, researchers have developed very specific tools and measurements to measure the outcomes of their studies.
Let’s take a look at how one study measured treatment success: In a study done at Brown University, researchers studied the success of transcranial magnetic stimulation (TMS). TMS is an outpatient treatment for patients with depression that have not responded well to other forms of treatment. TMS treatment stimulates the mood centers of the brain using non-invasive magnetic waves. This study looked at patients throughout the United states who had a diagnosis of depression, and who had not responded well to other treatments. (1)
Studies carefully measure the symptoms of depression of each patient before, during, and after treatment.
Often, the tools used to measure depression include one questionnaire that the patient answers before, during, and after treatment, where they self-report their symptoms. The patient is also evaluated before, during, and after treatment by mental health clinicians using specific scales designed to measure depression.
In the Brown University study on TMS, participants were evaluated using a questionnaire at beginning the study, and again at weeks two, four, and six (the last week of the study for most participants). One of the methods that clinicians used to measure depressive symptoms was a scale that looked similar to this one: (2)
Before beginning treatment, all patients were evaluated using the above scale. The average level of depression was a 5.1, or “markedly ill.” The study wanted to see if TMS treatment could to reduce depression to a value of 3 or lower on the scale.
For some patients, successful treatment means that their depression has decreased and has become more manageable.
When a patient improves as a result of treatment, researchers label that improvement “response.” Brown University’s study defined response as anywhere between a 2.1 and a 3 on the 7-point scale scale:
At the end of the study, patients were evaluated by clinicians to assess their symptoms. The response rate was 58%. This means that more than half of the participants who completed treatment had experienced a reduction in their symptoms of depression.
For other patients, treatment success means that their depression is mostly or completely relieved.
When a patient’s depression is mostly or completely relieved, researchers call that outcome “remission.” As an example, let’s look again at the scale. Patients evaluated as being a 1 or a 2 on this scale after treatment are considered to be in remission.
The Brown University study found a remission rate of 37.1%. This means that more than one out of every three patients in this study experienced relief from depression.
Both outcomes—response and remission—are considered positive treatment outcomes.
In studies of depression, patients whose treatment results in either response or remission are no longer experiencing the severe depression they once had.
Overall, the response and remission rates from the Brown University TMS study, as well as others, demonstrate that TMS has been successful in treating depression. If you would like to find out more about TMS treatment, visit our What is TMS? page.
- Carpenter LL, Janicak PG, Aaronson ST, et al. Transcranial magnetic stimulation (TMS) for major depression: A multisite, naturalistic, observational study of acute treatment outcomes in clinical practice. Depress Anxiety. 2012 Jul; 29(7):587-96. Click Here. Accessed April 19, 2018.
- Busner J, Targum SD. The Clinical Global Impressions Scale: Applying a research tool in clinical practice. Psychiatry (Edgmont). 2007 Jul; 4(7):28–37. Click Here. Accessed April 19, 2018.