Based on the symptoms experienced as a result of lower levels of dopamine, it is thought that dopamine plays just as big of a role as serotonin in treating depression. Why then are medications used to treat depression primarily dealing with targeting serotonin only? Because people have been brainwashed by pharmaceutical companies? Maybe. It could be though that many people simply have not tried increasing their dopamine to determine whether they notice an antidepressant effect.
Depression itself is pretty subjective and can have a number of causes. It could be caused by trauma, a difficult childhood, abuse, drug usage, and other external events. It can also be caused by genetics and biological factors. Someone may have experienced developmental problems in the womb or have been exposed to certain toxins. This may lead to the development of depression. There is absolutely no clear cut evidence that low neurotransmitter levels even cause depression.
However, many people believe that “serotonin” may have something to do with depression because SSRI’s are the primary class of drugs used to treat it. Although serotonin may be the neurotransmitter most talked about when it comes to depression, my guess is that dopamine plays just as big of a role – if not a bigger role in depression.
Low dopamine vs. low serotonin… Which causes depression?
The reason I tend to think dopamine plays a huge role in treating depression is because if you look at individuals with low dopamine, they have difficulties with memory, thinking, organization, and experience an inability to feel pleasure. Many people with schizophrenia have abnormally low dopamine and as a result aren’t able to get motivated or stay productive.
Low dopamine: Tends to result in symptoms similar to Parkinson’s disease. People with abnormally low levels of dopamine may have difficulties with thinking, memory, and have slow reaction times. They may also experience anhedonia or lack of ability to feel pleasure. They may also feel similar to individuals with negative symptoms of schizophrenia in regards to having no motivation (avolition).
Low serotonin: Results in OCD-like symptoms including obsessive thoughts and compulsive behaviors. It also may result in impulsivity, feeling suicidal, aggressive behavior, etc. Lower levels of serotonin are linked to mood swings, sugar cravings, worrying, insomnia, and sadness.
There is some overlap between serotonin and dopamine that cannot be ignored. Some people do respond very well to SSRI’s and the increase in serotonin may be helping. With that said, many drugs like Paxil may indirectly affect dopamine receptors in the brain and actually improve them. So there can be certain links between SSRI’s and dopamine.
Dopamine vs. Serotonin for Depression Treatment
I tend to think that in most cases, people who respond well to SSRI antidepressants should just stay on them – they have been proven to work. With that said, there are many people for whom these drugs do not work very well. They also come with unwanted side effects and many people have gone through the entire wringer of medications only to find no relief. What ends up happening is that people end up staying on these medications and come off them with abnormally low levels of serotonin.
So the withdrawal is overwhelmingly difficult and the people have a difficult time coping with low serotonin. In many cases, the original problem wasn’t necessarily low serotonin, it may have been abnormally low dopamine. In this case, now the individual has abnormally low serotonin as well as low dopamine. If the individual would have targeted their dopamine first, they may have had success than experimenting with drugs that primarily affect serotonin.
I have had success in using Adderall for depression as well as anxiety. My personal experience is that some individuals with depression and/or anxiety may respond very well to medications that deal with dopamine more than they do serotonin.
- Source: http://www.ncbi.nlm.nih.gov/pubmed/17187269
- Source: http://www.ncbi.nlm.nih.gov/pubmed/8099801
Triple Reuptake Inhibitors: New Antidepressants
It seems as though researchers are catching on though and are trying to develop medications that target serotonin, norepinephrine, as well as dopamine. I tend to think that although this development could be useful, it sounds a bit overcomplicated. Many people do not need to tinker with all three neurotransmitters at the same time.
It would be much more favorable to simply target either dopamine or serotonin in my opinion and determine which class of drugs works better. The triple reuptake of neurotransmitters serotonin, norepinephrine, and dopamine sounds more and more like taking an illicit drug. I can only imagine how horrendous the withdrawal would be from something that tinkers with that many neurotransmitters.
The major difference between these medications and older ones is that they include the reuptake inhibition of dopamine. Although Wellbutrin can inhibit reuptake dopamine, it does it to a very little degree. Most dopamine reuptake inhibitors are weak in their reuptake of actual dopamine. With that said, this could be a reason why using Wellbutrin for ADHD works in some cases.