Neuroskeptic covers a fascinating case of a man born with a genetic mutation meaning he had a severe lifelong deficiency of both serotonin and dopamine.
The case report concerns a gentleman with sepiapterin reductase deficiency, a genetic condition which prevents the production of the enzyme sepiapterin reductase which is essential in the synthesis of both dopamine and serotonin.
The most widely recognised symptoms of the condition, linked to the deficiency in dopamine which has an important role in controlling movement, are problems coordinating both conscious movements and the unconscious control of muscles that allows simple actions. Unconscious control requires that the brain signals one muscle to contract while releasing the complementary muscle, and problems with this process cause spasticity.
The effects the condition on serotonin, often stereotyped as the ‘happy chemical’, are less well known, but in this case it was clear that the patient wasn’t depressed but did some other difficulties:
These included increased appetite – he ate constantly, and was moderately obese – mild cognitive impairment, and disrupted sleep:
“The patient reported sleep problems since childhood. He would sleep 1 or 2 times every day since childhood and was awake during more than 2 hours most nights since adolescence. At the time of the first interview, the night sleep was irregular with a sleep onset at 22:00 and offset between 02:00 and 03:00. He often needed 1 or 2 spontaneous, long (2- to 5-h) naps during the daytime.”
After doctors did a genetic test and diagnosed SRD, they treated him with 5HTP, a precursor to serotonin. The patient’s sleep cycle immediately normalized, his appetite was reduced and his concentration and cognitive function improved (although that may have been because he was less tired)…
Overall, though, the biggest finding here was a non-finding: this patient wasn’t depressed, despite having much reduced serotonin levels. This is further evidence that serotonin isn’t the “happy chemical” in any simple sense.
This is another piece of evidence against the common myth that depression is “caused by low serotonin” although Neuroskeptic speculates whether the link between disrupted sleep and depression may indicate an effect of serotonin dysfnction.
Link to Neuroskeptic on ‘Life Without Serotonin’.
Link to summary of scientific paper.
5 Comments
If someone had no serotonin how would they react to new variant Creutzfeldt-Jakob disease? would they be violent?
However, serotonin is not exactly a “hapy brain chemcial”. It is actually a mood regulator. Dopamine however IS a “feel good” neurotransmitter.
My theories on why he wasn’t depressed are…
1. He was able to generate just enough dopamine to keep himself happy.
2. Another feel good hormone is phenyethylamine, it could have been he was able to produce enough of this to keep himself happy.
3. If serotonin IS an anti-depressant, he was able to make enough of it to mantain a happy disposition.
4. He DID have just enough serotonin to keep him happy (in the case it is the anti-epressant neurotransmitter).
5. There IS a type of depression that we do not fully see as ‘true depression’. There are actually various types of depression, but not all of them have the classic stereotyped “oh, life is horribly unbarable…” sadness. This depression has sympoms like apethy, lethargy, chronic boredom, fatigue and thus, feeling the need to sleep a lot, (otherwise known has ‘the blahs’ by Julia Ross) which it sounds like he had. Thus, he could have very well been depressed, just not the sad, pitiful “woe is me” type we so often diagnose as depression.
hello
i used to take many medicine to raise my serotonine level in my brain
i ve been 10 years in this way
please please i need some help to get me out of this……………….
thanks a lot if anyone could help…..
Tried any medicine to raise your dopamine level instead?
These article shows how little do we know about serotonin, its receptors and precursors. But we still give these type of medicine to people and test it on them.
Shame on US!