David PerlmutterPresident,, Perlmutter Health Center · Board-Certified Neurologist | Functional Medicine Pioneer | #1 New York Times Best-Selling Author | International Speaker | Host of The Empowering Neurologist Podcast

A Surprising Link Between Alzheimer’s and Autism

3 Jun 2026 · 1 min

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1:21

In this brief YouTube monologue, board‑certified neurologist Dr. David Perlmutter explains that the immune‑mediated process of synaptic pruning—whereby unused neural connections are eliminated—plays a pivotal role in both autism and Alzheimer’s disease. He describes how, during early development, effective pruning refines brain circuitry, but in autism this process may be insufficient, leading to hyper‑connectivity. Conversely, in Alzheimer’s disease a re‑activation of pruning results in excessive loss of synapses, contributing to cognitive decline. Perlmutter emphasizes that synapse destruction is a central, shared mechanism linking these seemingly disparate conditions.

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Interestingly, Alzheimer's and autism share a very important mechanism. Hi, I'm Dr. David Perlmutter. I'm a board-certified neurologist, and it turns out that the notion of what is called synaptic pruning— what in the heck does that mean? It means having our immune system digest away our synapses— is actually playing a role in both autism and in Alzheimer's. In autism, What may be happening is we're not synaptic pruning enough. What did I just say? Isn't that interesting? That synaptic pruning is something that's actually good for the brain early in life. When we prune away unused synapses, we are refining and streamlining the brain. That's a normal process. It's been demonstrated that the brain in autism is actually hyperconnected. This normal process of synaptic pruning, getting rid of certain synapses, isn't as effective. That's a normal activity that may be reactivated in the Alzheimer's brain. Interestingly, that in the Alzheimer's brain, it's thought that there's reactivation of this developmental process whereby our synapses are reduced. The bottom line in Alzheimer's, it's, it is a loss of synapses. So incredible that synapses and their destruction is playing a central role in both of these issues.