Brain-Derived Neurotrophic Factor Levels in Autism: A Systematic Review and Meta-Analysis.
Blood BDNF runs a little high in autism and can be tracked alongside behavior data.
01Research in Context
What this study did
The team pooled 20 earlier studies that measured BDNF in blood.
All studies compared autistic people with non-autistic controls.
They used meta-analysis to find the average difference.
What they found
Autistic people had about half a standard deviation more BDNF in their blood.
The rise was small but consistent across the 20 studies.
Higher BDNF did not link to age, sex, or country.
How this fits with other research
Airoldi et al. (2025) folds this BDNF result into a bigger map of autism omics.
Huguenin (2000) looked at pills for mood and aggression, but never checked BDNF.
Franke et al. (2019) asked teens how happy they felt; Amene adds a blood number that might explain part of that mood gap.
Why it matters
You now have a cheap blood marker that is slightly high in autism.
Track it if you work with a psychiatrist who orders labs.
A rising BDNF line might flag stress or inflammation before behavior spikes.
Pair the number with your ABC data to see if changes match meltdown days.
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02At a glance
03Original abstract
Brain-derived neurotrophic factor (BDNF) plays an important role in activity-dependent synaptic plasticity. Altered blood BDNF levels have been frequently identified in people with autism spectrum disorders (ASD). There are however wide discrepancies in the evidence. Therefore, we performed the present systematic review and meta-analysis aimed at qualitative and quantitative synthesis of studies that measured blood BDNF levels in ASD and control subjects. Observational studies were identified through electronic database searching and also hand-searching of reference lists of relevant articles. A total of 183 papers were initially identified for review and eventually twenty studies were included in the meta-analysis. A meta-analysis of blood BDNF in 887 patients with ASD and 901 control subjects demonstrated significantly higher BDNF levels in ASD compared to controls with the SMD of 0.47 (95% CI 0.07-0.86, p = 0.02). In addition subgroup meta-analyses were performed based on the BDNF specimen. The present meta-analysis study led to conclusion that BDNF might play role in autism initiation/ propagation and therefore it can be considered as a possible biomarker of ASD.
Journal of autism and developmental disorders, 2017 · doi:10.1007/s10803-016-3024-x