Ask an expert

17 Feb 2003

Is there any way to test a person's Serotonin levels?
I was just wondering - how does a doctor go about testing if you have 'low levels of serotonin' available in your brain? I've read that there is some controversy about it - that some people have their levels of serotonin lowered in medical experiments and that it does not lead to a depression, or other mental illness. Yet, doctors are quick to tell you (without tests) that you have low levels of serotonin and some other neuro-transmitters - which justify the use of chemical intervention. Am I missing something here? (I've been waking up at night and I sometimes have heartpalpitations. I went to two different GP's with the problem and both said it was due to 'low levels of serotonin' causing anxiety attacks or depression. They only took my bp and heartrate - which were both normal. And I had some bloodtests done (to rule out diabetes, etc. How do they come to the depression conclusion?? I work for a Pharm. Lab - and their claims do not seem to be consistent with what I know.)

I would really appreciate your expert view on this matter.
Answer 1,268 views

01 Jan 0001

Dear Misscurious,
An interesting question. And firstly, let m say that I think a few too many doctors, especially GPs, are nowadays far too ready to talk airily of "chemical imbalance of the serotonin levels" without a firm basis for this, or without a good understanding of the chemistry involved !
Leaving aside impractical and experimental procedures, there is no useful practical way to measure your serotonin levels, not in the way that one can measure a blood-sugar level in tests for diabetes. And even then, when one's interested in these dynamically changing levels, its better to take a series of blood sugar levels, for instance, under specifically controlled circumstances, to be sure of how they are behaving.
Without going into long and complex discussion of experimental data, there is a lot of evidence suggesting that serotonin levels are awry in depression, and a number of related conditions, including the fact that drugs which raise and normalize serotonin levels tend to relieve such conditions. Often, we have to rely on indirect measures. For instance, when someone shows symptoms typical of those of someone with low levels of blood sugar, and it's not immediately practical to measure blood sugar, if you give them a sweet juice to drink, such as would raise their blood sugar levels, and it relieves the symptoms, the theory that a low blood sugar caused the symptoms, is supported.
Remember also, that what is relevant, is the relative concentrations of serotonin ( and some other brain chemicals ) within specific areas of brain. And these can only ( in living peopl ) be measured indirectly, at best
I know of no convincing experiments in which people had their serotonin levels lowered, and dob that his would be practical to do well, within a sound experiment, for a sufficient period of time. And because changes in one brain chemical usually leads automatically to changes in others, it's not always easy to be sure what was achieved in such a study. One wouldn't be able to take actual samples from the relevant areas of the living brain, to measure accurately the exact levels of chemicals in the parts of the brain which interest us.
In a situation like yours, where you have some symptoms, what'd be most useful would be for a GP to compare those with recognized patterns of symptoms to make a clear diagnosis, and then to try the appropriate treatments for those. And if the issue is unclear, maybe to refer you to a psychiatrist, for a more detailed discussion specifically relaed to your particular situation.
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical examination, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.