Chris Williamson · 2024-09-09 · Andrew Huberman, Chris Williamson (host)
Why You’re Tired, Unmotivated, and Unfocused - Dr. Andrew Huberman (4K)
60 claims checked against research: 6 contradicted 3 overstated 6 needing context 34 supported 2 corroborated online 9 unverified
6 Contradicted by research
Rapid eye movement (REM) sleep has been used as a clinical treatment for depression.
"rapid eye movement sleep has also been used as a clinical treatment for depression, right?" (said at 0:17:26)
The speaker claimed that rapid eye movement (REM) sleep has been used as a clinical treatment for depression. In clinical psychiatry and sleep research, it is REM sleep deprivation (or REM sleep suppression), rather than REM sleep itself, that has been studied and utilized as a therapeutic intervention. Randomized clinical trials showed that selectively preventing patients from entering REM sleep (or total sleep deprivation) produced rapid antidepressant responses, and many clinical antidepressant medications function by suppressing REM sleep. Asserting that REM sleep itself is the therapeutic agent inverts the actual clinical intervention.
When alerted or triggered, locus coeruleus neurons disperse epinephrine/adrenaline across the brain, and adrenals release adrenaline in parallel within hundreds of milliseconds.
"that structure of neurons, that cluster in the in the brainstem called the locus coeruleus—let's just stay with, you know, broad nomenclature—has there's clusters of neurons that do many different things there, but some of them provide, you know, these wire-like axonal inputs, as we call them, in a kind of sprinkler fashion to the brain. And when there's something that alerts us that we need, you know, it's triggering to us, if you will, it just... sprinklers the brain with epinephrine, adrenaline, and boom, the brain wakes up. And then in parallel, your adrenals release adrenaline, and within, you know, a couple hundred milliseconds, you're up" (said at 1:07:39)
The speaker incorrectly identifies epinephrine (adrenaline) as the neurotransmitter released by the locus coeruleus throughout the brain. The primary neurotransmitter synthesized and released by locus coeruleus neurons across diffuse cerebral projections is norepinephrine (noradrenaline), not epinephrine. Epinephrine in the central nervous system is produced by distinct adrenergic cell groups in the medulla, while peripheral epinephrine is secreted as a hormone into the bloodstream by the adrenal medulla during stress, operating on a hormonal timescale rather than a millisecond neurotransmitter release mechanism.
- contradicts: Noradrenaline Regulation of Brain-Body Communication. (Advances in experimental medicine and biology 2025) · cited 4x in the literature
"In the central nervous system (CNS), NE acts as a neurotransmitter, primarily released by the locus coeruleus (LC), to regulate vigilance states and optimize behavioral performance. It is also the primary neurotransmitter of the peripheral, sympathetic nervous system, responsible for tonic and reflexive changes to cardiovascular tone. Conversely, Epi operates primarily as a hormone released by the adrenal medulla, to regulate metabolic homeostasis and orchestrate the body's response to acute stress." (abstract, passage verified)
pubmedfull study (doi) - contradicts: Locus Coeruleus as a Master Regulator of Diverse Functions in the Central Nervous System: … (Annals of neurosciences 2026)
"The main neurotransmitter synthesised by these neurons is norepinephrine (NE), which polymerises to NM." (abstract, passage verified)
pubmedfull study (doi)
Some caterpillar species have evolved poisons that do not kill predatory birds, allowing birds to survive and feed the caterpillars to their offspring, which then form a permanent memory to avoid eating those caterpillars.
"Like some of them have adapted different poisons so that the birds that eat them don't die, but literally survive and transmit the discomfort by feeding their young, and then the young are like, "Uh..." and they actually form a permanent memory not to eat those caterpillars." (said at 1:31:14)
Chemical defenses in caterpillars and other aposematic insects evolve to reduce predation through direct unprofitability (such as emesis, foul taste, or mild toxicity) that induces individual avoidance learning or reinforces innate wariness in the foraging predator itself. No published evidence supports the claim that caterpillar toxins evolved to spare adult birds specifically so parents could feed the prey to their nestlings to transmit an avoidance memory across generations. Studies on avian learned avoidance show that individual predators learn directly through their own foraging encounters with defended prey.
- contradicts: The costs and effectiveness of chemical defenses in herbivorous insects: a meta‐analysis (Ecological Monographs 2015) · cited 122x in the literature
"The chemical defenses of insect herbivores, on average, were effective against generalist predators, were not effective against specialist predators and generalist parasitoids, and increased the risk of parasitism by specialist parasitoids. The defenses were more effective against vertebrate than against invertebrate predators and most effective against birds... Aposematic colors and patterns were more effective warning signals than other types of conspicuous coloration against both experienced and naïve vertebrate predators, suggesting that certain colors and/or patterns were more important than conspicuousness for both learning and innate avoidance." (abstract, results, passage verified)
openalexfull study (doi) - contradicts: Predator learning differences affect the survival of chemically defended prey (Animal Behaviour 2017) · cited 18x in the literature
"We found that strains differed in how they learned about chemically defended prey, which resulted in significant differences in prey survival... Predators' initial wariness of novel prey was not related to learning at the strain or individual level, but predator wariness increased after exposure to chemical defences." (abstract, results)
openalexfull study (doi)
Nicotinamide mononucleotide (NMN) is a precursor to NAD+, and nicotinamide riboside (NR) is a precursor to NMN.
"Remember, NMN is a precursor to NAD; NR is the precursor to NMN, so there's a phosphate group that gets removed." (said at 2:23:30)
The speaker's statement bundles multiple assertions regarding the NAD+ salvage pathway. It is correct that nicotinamide mononucleotide (NMN) is an immediate precursor to NAD+ (via nicotinamide mononucleotide adenylyltransferases) and that nicotinamide riboside (NR) serves as a precursor to NMN. However, the speaker states the chemical mechanism backwards regarding phosphate modification: NR is a nucleoside (nicotinamide attached to ribose) lacking a phosphate, whereas NMN is a nucleotide containing a 5'-phosphate group. Converting NR to NMN requires the addition of a phosphate group (phosphorylation catalyzed by nicotinamide riboside kinases, NRK1/2), not the removal of a phosphate group. (A phosphate is removed only when converting NMN back into NR, such as during extracellular dephosphorylation by CD73).
Lacerations must be sutured within 6 hours of injury to avoid wound infection.
"He said, "You have to get in and get it stitched up within 6 hours." ... To avoid infection. To avoid infection. It's the infection that gets in there." (said at 2:43:45)
Modern clinical evidence and systematic reviews do not support a strict 6-hour 'golden period' rule for laceration closure to prevent infection. Infection risk in traumatic lacerations is primarily determined by wound characteristics (such as degree of contamination, wound length/width, and anatomical location, with lower extremities carrying higher risk) and patient factors (such as diabetes), along with adequate irrigation and debridement. Prospective studies and systematic reviews have found no significant difference in infection rates between simple lacerations repaired before versus after 6 to 12 or more hours.
The human nervous system contains trillions of individual neurons.
"And then you have literally trillions of neurons, nerve cells, that are independent of one another, little spheres that need to connect to one another in immensely precise ways" (said at 2:36:40)
Quantitative stereological and isotropic fractionator studies establish that the adult human brain contains approximately 86 billion neurons (and about an equal number of non-neuronal cells), not trillions. Even accounting for the peripheral and enteric nervous systems, the total number of neurons in the human body remains around 86 to 100 billion. The number that reaches into the trillions is the count of synaptic connections between neurons, rather than the number of neurons themselves.
Unverified means no publication matching the claim was located; it does not prove the claim false. Spotted an error? See the corrections policy - disputes from the people quoted are prioritized.