Relationships of whole blood serotonin and plasma norepinephrine within families.
High serotonin travels in autism families, so look at relatives before calling it a one-off lab quirk.
01Research in Context
What this study did
The team drew blood from autistic children and their parents and siblings.
They checked whole-blood serotonin and plasma norepinephrine levels.
Then they looked for parent-child matches on each chemical.
What they found
Serotonin levels lined up between the kids and their first-degree relatives.
Norepinephrine levels did not show the same family pattern.
High serotonin clustered in families, not just in the autistic child.
How this fits with other research
Northup et al. (1991) repeated the idea with platelets and got the same upward family trend.
Bachman et al. (1988) saw no serotonin rise in autistic kids, but they mixed in kids with schizophrenia and did not test relatives — that explains the clash.
Hranilovic et al. (2007) moved the marker to adults and linked higher serotonin to poorer early speech, stretching the finding past childhood.
Goldberg et al. (2009) flipped the direction in parents: fewer serotonin-2 receptors, showing the family serotonin story is more than just high blood levels.
Why it matters
You cannot treat serotonin, but you can ask about family history.
If an autistic client has high serotonin, odds are a parent or sibling might too.
Share this with the medical team before anyone blames diet or meds.
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02At a glance
03Original abstract
Whole blood serotonin (5HT) and plasma norepinephrine (NE) levels were determined in 47 families of autistic probands to study relationships within families of these measures. Whole blood 5HT, but not plasma NE, was significantly positively correlated between autistic children and their mothers, fathers, and siblings. Twenty-three of the 47 families studied had at least 1 hyperserotonemic member. Of these 23 families, 10 (43.5%) had 2 or more hyperserotonemic members; 5 families were identified in which each family member studied had hyperserotonemia (whole blood 5HT greater than 270 ng/ml). If the autistic child of a family was hyperserotonemic, the first-degree relatives were 2.4 times more likely to be hypersertonemic than if the autistic child was not hyperserotonemic. Mean whole blood 5HT levels were higher in autistic subjects than their parents or siblings. Siblings were found to have lower plasma NE than autistic probands. This study replicates a previous study showing familial relationships of hyperserotonemia within families with autistic children.
Journal of autism and developmental disorders, 1990 · doi:10.1007/BF02216055