By: Emily Kapustin and Keiran Pace
Major depressive disorder, more colloquially referred to as depression, is a mood disorder that causes persistent feelings of sadness in a person, affecting how one feels, thinks, and behaves.¹ It is one of the most common mental illnesses in the world, with over 280 million people worldwide suffering from it.² The first line of treatment for MDD are selective serotonin reuptake inhibitors (SSRIs) which are drugs used as antidepressants. SSRIs work by releasing serotonin, a neurotransmitter that positively influences mood, emotion, and sleep.³ After the serotonin is released into the nerve cells, the SSRI blocks its reuptake, meaning that it does not get reabsorbed by the nerve cells. This allows for more serotonin to be available and passed further throughout the brain.² Figure 1 below summarizes the mechanism of action of SSRIs. Unfortunately, SSRIs do not work for everyone. In fact, research shows that up to 30% of patients fail to respond to typical antidepressant medications and have to turn to alternative treatment strategies.⁴ Fortunately, there are many other strategies that can treat and relieve symptoms MDD, including different forms of therapy, changing one’s diet, and the use of bright light.
Figure 1. An Overview of the Mechanisms of Action of SSRIs.¹
One common treatment for depression that is often used alongside medication and/or if SSRIs are not effective is therapy. Therapy is a broad practice that has many different applications and several types of branches. From traditional one-on-one conversational therapy to electroconvulsive therapy (ECT), each form of therapy has unique applications for those who suffer from treatment-resistant depression (TRD). Psychotherapy emotionally alters patients’ self-regard, helping them to recognize that they are not “defective” but rather ill.⁵ Cognitive behavioural therapy (CBT), a type of psychotherapy, is an extremely popular form of therapy and its effects on those with TRD are promising. On the other hand, electroconvulsive therapy (ECT) is another form of therapy that has yielded encouraging results for those with TRD. Electroconvulsive therapy works by having the patient put under anesthesia and passing small, controlled electric currents between two electrodes that are applied to the surface of the scalp. These currents pass through the electrodes and cause a therapeutic seizure that lasts anywhere between 20 and 90 seconds.⁶ Research has shown that 60 to 80 percent of people with depression achieve remission with a course of ECT.⁶
Figure 2. Electroconvulsive Therapy.²
Diet is another non-medicinal approach to alleviate symptoms of depression for individuals who do not respond to medication. A study conducted in Australia investigated how a change in diet could alter the effects of depression. Dubbed the “SMILES” trial (supporting the modification of lifestyle in lowered emotional states), it was the first trial to test dietary improvement as a treatment strategy for depression.⁷ The study was conducted in a sample of participants with MDD who had poor dietary quality before their enrolment in the experiment.⁸ Participants consumed a modified Mediterranean diet based on the Australian Dietary guidelines and the Dietary Guidelines for Adults in Greece. The diet is rich in vegetables, fruit, and whole grains with an emphasis on increased consumption of oily fish, olive oil, legumes, and raw unsalted nuts. After the 12-week trial period, those who consumed the Mediterranean diet showed significant improvement in depression symptoms between the baseline and 12 weeks as per the MADRS (Montgomery– Åsberg Depression Rating Scale) compared to those who did not modify their diet.⁸ The results of this trial show that diet quality can ameliorate depressive symptoms.
A third alternative to SSRIs for those with treatment-resistant depression is light therapy. While light therapy is commonly used for those with seasonal affective disorder (SAD), it can also be used for those with TRD. Light therapy works by using a special type of fluorescent light, called a light box. Light therapy is usually prescribed for 30 minutes to 2 hours a day. You place the light box away from you on a desk or table and sit in front of it while carrying out daily activities, such as eating, reading, or working.⁹ A study published in 2021 had participants with TRD split into two groups: one with repetitive transcranial magnetic stimulation (rTMS) - a treatment that uses magnetic pulses to stimulate nerve cells in the region of the brain that is involved in mood control and depression- and one with rTMS and bright light therapy (BLT). The study found that participants that underwent BLT showed significantly better scores on the Hamilton depression rating scale (HRDS) than participants in the group without BLT.¹⁰,¹¹ Another study conducted in 2015 reached the same conclusion. Participants underwent 3 weeks of BLT and within the first week, there was a statistically significant reduction in HDRS scores, and even after 5 weeks after BLT discontinuation, many participants still showed a treatment response.¹²
Figure 3. Bright Light Therapy Lamp Positioning.³
In conclusion, even though there is a first line of treatment for MDD, with the treatment being SSRIs, there are individuals who are resistant to this type of treatment and other antidepressant medications. There are also individuals who simply do not want to undertake pharmacological interventions to treat their depression or individuals who cannot take SSRIs because of interaction effects with other drugs and other reasons. Thankfully, there are many alternatives that have been studied and found to be effective for these populations. These forms of treatment include, but are not limited to: therapy, changes to diet, and the use of bright light. Research into TRD and other potential treatments for depression to support individuals who do not respond to first line treatment is ongoing and even on the rise. This can be attributed to society leaning more towards personalized medicine, the idea of tailoring patient care with considerations of his/her situation rather than with a “one size fits all” approach. This theme reiterates an important idea elucidated by Dr. Melissa Cady, “Personalized medicine is an art that advocates for the patient, not the pocket or convenience of the medical system.”¹³
Reference List:
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Images
1.Varvatsis C. SSRIs: everything you need to know. Ro. Published June 25, 2021. Accessed November 17, 2022. https://ro.co/health-guide/ssris-everything-you-need-to-know/
2. Electroconvulsive Therapy Cost in Hyderabad, India | Medicover. Medicoverhospitals.in. Published 2022. Accessed November 17, 2022. https://www.medicoverhospitals.in/surgery-cost/electroconvulsive-therapy-cost
3. Landgraf B. The 2022 Ultimate Guide to Bright Light Therapy. Carex. Published November 23, 2020. Accessed November 20, 2022. https://carex.com/blogs/resources/bright-light-therapy-guide