I’ve seen many interesting posts on our site discussing depression, such as the correlation between sleep and depression, how school work can affect depression, and so on and so forth. While I think these are worthwhile topics, I am going to take a different approach to looking at depression. I am going to examine some of the long-term effects of using antidepressants, and whether these effects are harmful, beneficial, or are evened-out in the long run.
So, what are antidepressants used for? Antidepressants, specifically SSRI’s, are prescribed to people with depression or anxiety. To simply put it, these medications help to increase the amount of serotonin in the brain, a neurotransmitter that many depressed and other mentally ill people lack. These SSRI’s prevent the excess re-absorption that typically occurs in depressed brains and causes people to be depressed, as seen in the picture on the left.
As with any medication, the list of potential side effects is never ending. To name a few side effects of SSRI’s, there can be insomnia, dry mouth, drowsiness, and diarrhea (Mayo Clinic). Generally, these side affects subside after the first few weeks as you regularly take the medication. But what about some of the long-term side affects? Personally, I found that after being on an SSRI for a long period of time, I didn’t feel depressed, but I didn’t feel happy either. I just felt nothing. This made me curious to see if others experienced the same feelings I did, or experienced other consequences of taking a SSRI for a long period of time.
So my hypothesis test would then be:
Null hypothesis: Long-term use of antidepressants has no effect on the antidepressant’s ability to function.
Alternative hypothesis: Long-term use of antidepressants has an effect on the antidepressant’s ability to function.
It turns out that other people experienced the same effect of taking a SSRI for a long time as I did. Harvard Health Publications states that there can be a loss of effectiveness for SSRI’S when taken for long periods of time, such as for a few months or a year. This is believed to be due to the fact that the brain develops a tolerance for the drug, so it is no longer as effective as it used to be.
In a study published the the Journal of Clinical Psychiatry, people who were on SSRI’s for MDD, or Major Depressive Disorder, and considered to be relieved of their depressive symptoms, were followed for three months. The subjects of the study were interviewed frequently throughout the three months of taking SSRI’s and asked about their mental health. The results showed that the longer the people were on the medication, the more likely they were to have physical and cognitive symptoms of depression again, with a reported p-value=.0002. This supports the alternative hypothesis that long-term use of antidepressants affects SSRI’s ability to function, specifically in a negative manner.
This study suggests a negative relationship, meaning the longer you use the antidepressant, the less effective it will be. However, since the study is an observational study, it is hard to rule out confounding variables that could cause someone to be depressed, such as the loss of a family member, the loss of a job, etc.
Now there is a possibility that this issue suffers from the file-drawer problem, because if a study found that the long-term use of antidepressants does not cause a loss of effectiveness of the drug, that would support the null hypothesis and be considered boring.
Overall, I think there should be more studies done to test these hypotheses, especially because SSRI’s are being prescribed more and more. If SSRI’s become ineffective after so much time, research should be done to find more effective ways of medically treating depression.