Antidepressants are commonly prescribed in the United States and the most common antidepressants are a group of drugs called selective serotonin reuptake inhibitors (SSRIs). Names of popular SSRIs include Lexapro, Zoloft, and Prozac.
Antidepressants, including SSRIs, are used to treat a variety of conditions including: anxiety disorders, major depression, posttraumatic stress disorder (PTSD), fibromyalgia, obsessive compulsive disorder, and eating disorders.
Given how popular antidepressants are, one might think that we have a good grasp on why these drugs help a variety of conditions. Unfortunately, as outlined in an article posted at The Guardian, we do not actually have a great understanding of why antidepressants work.
We know that antidepressants work by targeting neurotransmitters in the brain. As such, it was believed that these neurotransmitters are the primary way to control depression. Models such as the 'monoamine hypothesis' or more specifically the 'serotonin hypothesis' were created that stated that the underactivity of monoamines (i.e., serotonin, dopamine, norepinephrine, epinephrine) is responsible for depression and other conditions.
However, there are problems with the monoamine hypothesis, including the fact that it can several weeks for antidepressants to work. Given that the changes to serotonin happen shortly after taking SSRIs, clearly the monoamine hypothesis cannot be the sole explanation.
Other explanations include having impaired neuroplasticity, or the ability to form new connections in the brain. This neuroplasticity hypothesis is supported by research that shows that antidepressants help increase neuroplasticity, although this tends to take a while (which corresponds nicely to why antidepressants might take a while to fully work).
Alternative explanations include there being inflammation in the brain which results in mental health symptoms or having maladaptive connections between different parts of the brain including the amygdala, the hippocampus, and the anterior cingulate cortex.
Basically, we do not really know why exactly antidepressants work and it may be due to a combination of all the theories just presented. This is perhaps not altogether all that surprising given how diverse a condition such as depression is, let alone other conditions such as generalized anxiety, PTSD, and eating disorders.
The future of research will be determining which medications and psychological treatments work for which specific populations with specific problems. For example, some treatments may work better for individuals who have depression that includes somatic symptoms and sleep disturbance compared to other individuals who have depression that includes hopelessness, suicidal ideation, and lack of interest in activities.
It is important for there to be continued research on depression and other mental health conditions so we can better understand why they occur. This will allow us to create better treatments that get at the source of the condition. One of the exciting and frustrating parts about mental health research is that we still do not necessarily know a lot about different mental health conditions. Future decades will likely involve a huge increase of our knowledge in these areas.
For now, meeting with a psychiatrist and/or mental health provider is the best course of action. There are pros and cons to medication and psychological treatment and each person has to decide what works best for her/him. Indeed combination treatment of medication and psychological treatment (ideally some form of cognitive-behavioral therapy) can be more effective than either treatment alone. While we may not know exactly why our treatments work, they do often work, so please reach out to providers if you believe you need some help.
Article link: https://www.theguardian.com/science/brain-flapping/2017/jul/10/how-do-antidepressants-actually-work
The Clinically Relevant Insights Blog, part of ShawnWilsonPhD.com, is a blog that shares news and research regarding psychology and wellness.