The neurotransmitter serotonin has a role in mood stability. The presence of it in the right amounts is thought to help people keep an even mood instead of experiencing depression or anxiety, but this simple explanation is incomplete at best. Expert psychopharmacologists, psychiatrists and neurologists know the matter is far more complex, and that there are least four, and possibly many more neurotransmitters that affect mood. The explanation of serotonin’s direct connection to mood serves to provide a rudimentary understanding of how things like antidepressants work, but it does not fully explain the ways in which neurotransmitters and other, as yet, unknown factors work in the brain to elevate or depress mood.
One question commonly asked about serotonin and mood is why there isn’t a test to measure brain levels of it so that things like depression can be diagnosed as chemical or otherwise. What is known is that this form of testing wouldn’t be adequate. The “amount” of this available neurotransmitter doesn’t seem to be the problem when mood deteriorates. Instead, if this chemical is primarily responsible for causing uneven mood, it’s the way the brain uses or reuptakes it.
The most well known drugs for depression are called selective serotonin reuptake inhibitors (SSRIs), and what these do is prevent certain receptors from grabbing the chemical and using it too quickly. This then corresponds to more of it being available, which may help address mood. Only some people who take SSRIs for conditions like anxiety or depression are not helped by them. The serotonin as sole mood regulator theory fails with this evidence.
Psychopharmacologists and other specialists already know this, and they have created medicines that affect some of the other known neurotransmitters like norepinephrine and GABA. Some people with undeniable depression are assisted with a class of medications known as selective norepinephrine and serotonin reuptake inhibitors (SNRIs). It makes sense to conclude that a single chemical is not responsible for mood stability.
Scientists certainly don’t refute the idea that serotonin can have a strong impact on mood. People who take too many SSRIs can develop psychosis. A person with bipolar disorder should avoid taking SSRIs. They can manifest bipolar disorder in some patients who are already predisposed, and in those with the condition, it may create mania or hypomania. Usually, there is little concern about participating in activities like exercise that raise levels of this chemical naturally.
It’s clear that the relationship between serotonin and mood is not totally understood. How the brain and its neurotransmitters affect mood remains a promising field of exploration. Presently, people who seem most affected by this lack of understanding are those who have not responded to traditional treatments for mood conditions or who have spent many years in treatment prior to arriving at the right combinations of medications that create symptom resolution.