Four Drugs, One Target: GSK3β and the Accidental Discovery of Why Psychedelics Treat Depression

Why ketamine, psilocybin, MDMA, and lithium all make the world feel brighter — and what that means for treatment

Carla — Draft, April 2026

The Observation

Four pharmacologically distinct substances produce a strikingly similar subjective experience in people with depression: the world feels brighter, colors are more vivid, things feel worth doing again, and the flat gray film that depression lays over experience lifts. These substances are:

• Ketamine — an NMDA receptor antagonist
• Psilocybin — a serotonin 5-HT2A receptor agonist
• MDMA — a serotonin/dopamine/norepinephrine releaser
• Lithium — a direct enzyme inhibitor

They bind different receptors. They affect different neurotransmitter systems. They are studied by different research communities who rarely cite each other. The ketamine people think the mechanism is glutamate. The psilocybin people think it’s serotonin. The MDMA people think it’s empathogenic bonding. The lithium people think it’s mood stabilization.

They are all wrong about why their drug works. Or rather, they are all partially right about their drug’s entry point and collectively blind to the shared destination.

All four converge on a single downstream target: glycogen synthase kinase 3 beta (GSK3β).

What Is GSK3β?

GSK3β is a kinase — an enzyme that phosphorylates other proteins, modifying their function. It was originally discovered in the context of glycogen metabolism, but it is now known to regulate an extraordinary range of cellular functions: neuronal survival, synaptic plasticity, neurotransmitter receptor trafficking, circadian rhythm, inflammation, and gene transcription. GSK3β has over 100 known substrates. It is expressed in every cell in the body but is particularly abundant in the brain, where a neuron-specific isoform (GSK3β2) predominates.

The critical property of GSK3β is that it is constitutively active. Unlike most kinases that are turned on by a signal, GSK3β is always on unless something is actively suppressing it. It is the default destruction mode. When left unopposed, GSK3β promotes apoptosis, degrades synaptic proteins, impairs BDNF signaling, disrupts circadian rhythms, and promotes neuroinflammation. The cell must continuously suppress GSK3β to maintain normal function.

The primary endogenous suppression pathway runs through cortisol: cortisol → glucocorticoid receptor (GR) → PI3K/Akt → phosphorylation of GSK3β at Ser9 → inhibition. When cortisol signaling is adequate and GR is functioning, GSK3β stays suppressed and the brain works normally. When cortisol is low, or GR is desensitized, or the upstream chain is broken for any reason, GSK3β becomes overactive.

Overactive GSK3β in the brain produces: reduced BDNF, dendritic spine retraction, impaired synaptic plasticity, disrupted dopamine and serotonin signaling, neuroinflammation, and circadian fragmentation. In animal models, GSK3β overactivation specifically in the nucleus accumbens (ventral striatum) produces depression-like behavior (Polter et al., 2010). Conversely, GSK3β knockin mice — animals engineered so GSK3β cannot be inhibited — show heightened vulnerability to stress-induced depression.

GSK3β is not “a factor in depression.” It may be the convergent molecular endpoint of depression itself.

An ecosystem analogy. The relationship between neurons, GSK3β, and cortisol resembles the relationship between a forest, deer, and wolves. Neurons and their dendritic spines are the forest — the living architecture that makes the brain functional. GSK3β is the deer — always grazing, always consuming, always degrading synaptic structure unless something keeps the population in check. Cortisol, acting through GR and the PI3K/Akt pathway, is the wolf — the predator that suppresses GSK3β and allows the forest to thrive.

When the ecosystem is balanced — adequate cortisol, functioning GR, GSK3β properly suppressed — the forest is healthy. Spines are maintained, BDNF flows, circuits work. Remove the wolves (low cortisol, desensitized GR, or FKBP51 blocking the chain), and the deer population explodes. The forest is consumed. This is depression: the synaptic architecture degrades because nothing is keeping GSK3β in check.

Lithium is the park ranger who shoots the deer directly. It does not need wolves. It does not need a functioning predator-prey chain. It just walks in and suppresses the population by hand.

But the park ranger must be careful not to eliminate the deer entirely. GSK3β is not purely destructive — it is the brain’s remodeling system. GSK3β is required for axon elongation, neuronal polarity, and the formation of new synaptic connections. It drives long-term depression (LTD) — the weakening of synapses that need to be weakened — which is as essential for learning as long-term potentiation (LTP), the strengthening of synapses. It phosphorylates cytoskeletal proteins to enable the disassembly and reorganization that synaptic remodeling requires. Complete deletion of GSK3β in hippocampal neurons actually REDUCES spine density and impairs memory (Liu et al., 2017; Ochs et al., 2015), because without the ability to prune and reorganize, no new learning can consolidate. A forest with zero deer becomes an overgrown, tangled mess where nothing new can grow. Moderate grazing is how forests stay healthy.

This means the goal of lithium treatment is not to suppress GSK3β to zero — it is to bring overactive GSK3β back to physiological levels. In a healthy brain with adequate cortisol signaling, GSK3β is already modulated to the right level by the endogenous cortisol → GR → Akt pathway. The problem in depression, burnout, and T-allele mismatch is not that GSK3β exists — it is that the endogenous suppression pathway has failed and GSK3β has become OVERACTIVE, tipping the balance from healthy remodeling to net destruction. Lithium at supplement doses (5-20mg lithium orotate) does not eliminate GSK3β. It nudges overactive GSK3β back toward the range where the endogenous system would have kept it if the cortisol-GR chain were working properly. The park ranger is not exterminating the deer. He is restoring the population to what the wolves would have maintained if they hadn’t disappeared.

The analogy is imperfect at the high end: too much cortisol does not simply produce “too many wolves keeping deer in perfect check.” Excessive cortisol causes its own damage through the nuclear GR pathway — active gene transcription that prunes dendrites independently of GSK3β. In the ecosystem metaphor, too many wolves start trampling the forest themselves even as they control the deer. The optimal state is a moderate wolf population: enough to keep GSK3β suppressed, not so much that GR-mediated nuclear transcription causes its own destruction. This is the inverted-U relationship between cortisol and brain function, and it explains why both too little and too much cortisol damage the brain — through different mechanisms operating through different GR pathways.

Four Entry Points, One Target

Ketamine → GSK3β

Ketamine blocks NMDA receptors, which triggers a cascade: NMDA antagonism → disinhibition of glutamate release → AMPA receptor activation → BDNF release → TrkB activation → PI3K/Akt activation → phosphorylation of GSK3β at Ser9 → inhibition.

This was demonstrated directly by Beurel et al. (2011), who showed that ketamine’s antidepressant effect in mice requires GSK3β inhibition. When they used GSK3β knockin mice (where GSK3β cannot be inhibited by phosphorylation), ketamine’s antidepressant effect was abolished. The drug still blocked NMDA receptors. It still released glutamate. It still activated AMPA. But without the ability to inhibit GSK3β at the end of the chain, none of it mattered.

The primary brain regions affected: prefrontal cortex and hippocampus, where NMDA receptor density and the specific interneuron circuitry that mediates disinhibition are strongest.

Psilocybin → GSK3β

Psilocin (the active metabolite of psilocybin) agonizes serotonin 5-HT2A receptors. 5-HT2A activation engages the PI3K/Akt signaling pathway → phosphorylation of GSK3β at Ser9 → inhibition.

Psilocybin also increases BDNF, which feeds back through TrkB to further suppress GSK3β. The acute psychedelic experience and the sustained antidepressant effect may operate through different mechanisms: the trip is 5-HT2A-mediated perception alteration; the lasting benefit is GSK3β-mediated synaptic remodeling.

The primary brain regions affected: cortical layer V pyramidal neurons, where 5-HT2A density is highest. Visual cortex is particularly dense in 5-HT2A, which explains the vivid visual effects. Less direct effect on the striatum.

MDMA → GSK3β

MDMA floods the synapse with serotonin, dopamine, and norepinephrine simultaneously by reversing their respective transporters. The serotonin surge activates 5-HT receptors → Akt → GSK3β inhibition. The dopamine surge additionally engages D2 receptor-mediated Akt signaling in the striatum → GSK3β inhibition.

MDMA is the only one of the four that produces massive dopamine release in the ventral striatum (nucleus accumbens), making it the substance most likely to inhibit GSK3β specifically in the reward circuit. This may explain why MDMA uniquely restores the feeling that social connection is rewarding and worth pursuing — it is hitting GSK3β in the brain region responsible for assigning value to social behavior.

The primary brain regions affected: broadly distributed due to multi-transmitter release, but with particular strength in the striatum and nucleus accumbens due to dopamine. This distinguishes MDMA from ketamine and psilocybin, which primarily affect cortical and hippocampal regions.

Lithium → GSK3β

Lithium inhibits GSK3β directly through competition with magnesium at the enzyme’s catalytic site. No receptor. No signaling cascade. No intermediate steps. Lithium binds GSK3β and stops it from working.

Lithium also inhibits GSK3β indirectly by increasing inhibitory Ser9 phosphorylation through disruption of the Akt/protein phosphatase 1 complex. Both mechanisms converge on the same result: GSK3β suppression.

The primary brain regions affected: everywhere. Lithium has no regional selectivity. It inhibits GSK3β in whatever cell it reaches. This is its unique advantage: it covers the prefrontal cortex (like ketamine), the visual cortex (like psilocybin), AND the striatum (like MDMA) simultaneously.

The Comparative Table

The Wider Network: Other GSK3β Inhibitors Hiding in Plain Sight

The four substances above are not the only GSK3β inhibitors. Once you know to look for this target, connections appear across pharmacology, nutrition, and metabolic medicine that have never been linked.

Insulin

Insulin was the original GSK3β suppression pathway — it is literally how GSK3β got its name. Insulin signaling → PI3K → Akt → phosphorylation of GSK3β at Ser9 → inhibition. GSK3β was discovered as the kinase that phosphorylates glycogen synthase, and insulin’s job is to suppress it so glycogen can be stored.

This has a provocative implication. Insulin resistance — which is elevated in depression, burnout, chronic stress, and metabolic syndrome — means LESS insulin-mediated GSK3β suppression. The well-documented comorbidity between depression and metabolic syndrome may not be two separate conditions that co-occur. They may share a single molecular mechanism: insufficient GSK3β suppression, manifesting as disordered glucose metabolism in the periphery and synaptic degradation in the brain simultaneously.

This also means that anything that improves insulin sensitivity — exercise, metformin, weight loss, reduced refined carbohydrate intake, adequate sleep — may partially suppress GSK3β as a side effect. The antidepressant effects of exercise, consistently demonstrated but mechanistically vague in the psychiatric literature, may operate partly through improved insulin signaling → better GSK3β suppression → BDNF maintenance → preserved synaptic architecture.

Zinc

Zinc directly inhibits GSK3β. Zinc deficiency is one of the most replicated nutritional findings in depression, and zinc supplementation has demonstrated antidepressant effects in multiple trials. The standard explanation invokes zinc’s role in NMDA receptor modulation. But zinc’s direct GSK3β inhibition provides a simpler and more parsimonious mechanism: zinc-deficient individuals have less GSK3β suppression; supplementation restores it.

Valproic Acid (Depakote)

Valproic acid is an anticonvulsant and mood stabilizer prescribed for bipolar disorder, epilepsy, and migraine prophylaxis. It inhibits GSK3β indirectly via the Akt pathway. It is already one of the most prescribed psychiatric medications in the world. Nobody frames it as a GSK3β inhibitor — it is discussed in terms of GABA enhancement and sodium channel modulation — but GSK3β inhibition may explain a significant portion of its mood-stabilizing effects, particularly given that its mood effects overlap substantially with lithium’s despite having a completely different receptor pharmacology.

Curcumin

Curcumin, the active compound in turmeric, is a natural product GSK3β inhibitor. The “turmeric for depression” wellness trend has been largely dismissed by academic psychiatry as placebo effect. If curcumin actually inhibits GSK3β in the brain at dietary doses — which is uncertain given curcumin’s poor bioavailability — then the wellness community may have stumbled onto the right target through the wrong reasoning.

The Pattern

When you list everything that inhibits GSK3β and ask “which of these have people claimed help depression,” the overlap is striking: lithium, ketamine, psilocybin, MDMA, exercise, zinc, valproic acid, insulin sensitizers, and curcumin. These substances come from different pharmacological classes, are studied by different research communities, and are recommended by different clinical traditions — psychiatry, psychedelic therapy, functional medicine, nutritional psychiatry, and wellness culture. Each community has its own explanation for why their intervention works. None of them has identified the shared downstream target.

The convergence on GSK3β does not mean GSK3β is the only mechanism of depression or that every antidepressant works through GSK3β. SSRIs, for example, have limited direct GSK3β effects, which may explain why they help some patients but not others — and why the patients they fail to help often respond to ketamine or lithium. The hypothesis is that GSK3β-mediated synaptic degradation represents one major pathway to depression, and patients whose depression runs primarily through this pathway will respond preferentially to GSK3β inhibitors regardless of which specific inhibitor is used.

Why This Matters

The psychiatric establishment has spent over a decade and billions of dollars proving that GSK3β inhibition treats depression. They just don’t know that’s what they proved.

The ketamine research community has run hundreds of clinical trials showing rapid antidepressant effects. The psilocybin community has produced landmark trials showing sustained remission from treatment-resistant depression. The MDMA community has achieved breakthrough therapy designation for PTSD. Each community believes their molecule is special. Each has built an entire clinical infrastructure around their specific substance.

None of them has stepped back and asked: what if they all work for the same reason?

If the convergent target is GSK3β, then the question is not “which psychedelic is best for depression.” The question is: what is the safest, most accessible, most sustainable way to keep GSK3β inhibited?

By every practical measure, the answer is lithium orotate.

The Striatal Gap: Why Ketamine Fails Some Patients

The regional specificity described in the table above has a clinical consequence that is rarely discussed. Ketamine’s GSK3β inhibition is concentrated in the prefrontal cortex and hippocampus — regions that mediate cognitive clarity, memory, and the ability to think clearly about the future. Many patients who receive ketamine infusions report that their “depression lifts” — the cognitive fog clears, the world seems navigable again, and they can think through problems they couldn’t approach before.

But a significant subset of ketamine patients report a puzzling partial response: they can think clearly, but they still cannot act. The fog lifts, but the motivation doesn’t return. They understand what they should do but feel no drive to do it. They describe themselves as “undepressed but still flat.” Clinicians often interpret this as incomplete response and recommend additional infusions.

The GSK3β framework offers a different explanation. These patients may have two problems, not one: GSK3β overactivation in the PFC/hippocampus (producing cognitive depression) AND GSK3β overactivation in the striatum (producing motivational collapse, anhedonia, and inability to initiate). Ketamine addresses the first but not the second. The PFC comes back online. The striatum stays dark.

This is because ketamine’s mechanism — NMDA antagonism → SST interneuron suppression → pyramidal cell disinhibition → glutamate surge → AMPA activation → Akt → GSK3β inhibition — depends on specific local circuit architecture (the somatostatin interneuron disinhibition pathway) that is strongest in cortical regions. The striatum is organized differently. Its principal neurons (medium spiny neurons) have different interneuron populations, different receptor distributions, and different circuit dynamics. The disinhibition cascade that makes ketamine so effective in the PFC may simply not engage in the striatum with the same force.

MDMA, by contrast, floods the striatum with dopamine directly — bypassing the local circuit architecture entirely. This may explain why MDMA-assisted therapy produces the emotional reconnection and motivational surge that ketamine does not: it is reaching the brain region that ketamine misses.

Lithium reaches both. It inhibits GSK3β everywhere, with no dependence on local circuit architecture, interneuron populations, or specific receptor distributions. A patient who responds partially to ketamine — clearer thinking but still flat — might achieve full response by adding lithium orotate to maintain GSK3β suppression in the striatum between ketamine sessions, or by using lithium as the primary intervention if the striatal deficit is the dominant problem.

This generates a testable prediction: partial ketamine responders (improved cognition, persistent anhedonia) should show preferential benefit from the addition of lithium orotate or from MDMA, compared to additional ketamine infusions targeting the same cortical regions that have already responded.

Lithium Orotate: The Maintenance Protocol

Lithium orotate is a lithium salt in which lithium is bound to orotic acid. It is available as an over-the-counter nutritional supplement at doses of 1-20mg. It is not prescription lithium carbonate, which is used at doses of 600-1200mg for bipolar disorder and requires therapeutic drug monitoring, blood draws, and kidney/thyroid surveillance.

A 2025 study in Nature (Aron et al., 2025) found that lithium orotate reaches brain tissue at therapeutic concentrations at approximately 1/1000th the dose of lithium carbonate. The orotate salt crosses the blood-brain barrier more efficiently and avoids sequestration by amyloid plaques that traps lithium carbonate. In mice, low-dose lithium orotate reversed memory loss, restored synapses, and prevented cognitive decline without evidence of toxicity over nearly the entire adult lifespan.

Lithium orotate at supplement doses (5-20mg) is pharmacologically and clinically distinct from prescription lithium:

• No therapeutic drug monitoring required
• No known renal toxicity at supplement doses
• No known thyroid toxicity at supplement doses (though monitoring is prudent with long-term use)
• Available without prescription
• Costs approximately $12 per month

The hypothesis: daily lithium orotate at 5-20mg provides sustained, continuous GSK3β inhibition equivalent to what periodic psychedelic sessions provide intermittently. It is the maintenance version of what ketamine, psilocybin, and MDMA do acutely. It does not produce a trip. It does not require a clinic. It does not require a therapist. It does not require breaking the law. It requires swallowing a pill before bed.

Beyond GSK3β Inhibition: What Lithium Does Downstream

When GSK3β is inhibited, several downstream effects follow:

BDNF upregulation. GSK3β inhibition → CREB activation → BDNF gene transcription. BDNF (brain-derived neurotrophic factor) is the primary growth and maintenance signal for dendritic spines — the synaptic connections that make neural circuits functional. Low BDNF is one of the most replicated findings in depression. Lithium raises it.

Dendritic spine maintenance. BDNF maintains dendritic spines in the striatum, prefrontal cortex, and hippocampus. Without adequate BDNF, spines retract, synapses are lost, and circuits degrade. This is the structural basis of depression: the hardware erodes. GSK3β inhibition via lithium provides activity-independent BDNF supply, maintaining spines even when the circuits themselves are quiet.

GR priming. Jeanneteau et al. (2015) demonstrated that BDNF directly phosphorylates glucocorticoid receptors (GR) at sites essential for neuroplasticity gene transcription. This means lithium-driven BDNF does not just maintain spines — it improves the sensitivity of cortisol receptors, making whatever cortisol IS present more effective. For individuals with low cortisol signaling (burnout, chronic stress recovery, FKBP5 T-allele carriers), this is particularly relevant: lithium makes the weak signal more audible rather than requiring the signal to be louder.

Glutamate regulation. Lithium modulates glutamate reuptake, preventing excitotoxicity while maintaining normal excitatory transmission. This may contribute to the subjective experience of “clarity” that lithium users report — noise is reduced without signal being suppressed.

Circadian stabilization. GSK3β phosphorylates core clock proteins including BMAL1 and Rev-erbα. Overactive GSK3β fragments circadian rhythms. Lithium stabilizes them. This may explain why lithium improves sleep quality and why many users report that taking it before bed produces better mornings.

Who Might Benefit

GSK3β overactivation is not limited to a single diagnostic category. Based on the mechanism, the following populations may benefit from sustained GSK3β inhibition via lithium orotate:

Depression (broadly). If overactive GSK3β is a convergent endpoint of depressive pathology regardless of upstream cause, then GSK3β inhibition may provide benefit across depression subtypes. This does not mean lithium replaces antidepressants for all patients. It means it may help the subset whose depression is driven by GSK3β-mediated synaptic degradation rather than monoamine deficiency.

Burnout recovery. Chronic stress depletes cortisol signaling → GR desensitization → loss of GSK3β suppression → BDNF falls → striatal spines retract → motivational collapse. Lithium provides the GSK3β inhibition that cortisol is no longer delivering. (See FKBP5.com for the full mechanistic model.)

Seasonal affective disorder. Reduced winter light → reduced cortisol drive → reduced GR-mediated GSK3β suppression → everything feels dim. Lithium provides GSK3β inhibition independent of photoperiod. It may not eliminate the seasonal oscillation in receptor sensitivity, but it raises the floor so that winter doesn’t drop below the functional threshold.

FKBP5 T-allele carriers with childhood adversity. These individuals have a permanently elevated cortisol activation threshold AND lower baseline cortisol production. Their GR chronically under-suppresses GSK3β regardless of environment or season. Lithium provides the downstream effect their cortisol-GR chain cannot. This may be a lifelong supplementation need, not a time-limited intervention. (See FKBP5.com for genotype details.)

Post-psychedelic maintenance. Patients who respond well to ketamine, psilocybin, or MDMA but relapse after weeks to months may be experiencing the return of unopposed GSK3β activity as the acute drug effect fades. Daily lithium orotate between sessions could maintain GSK3β suppression during the inter-session period, potentially extending the duration of benefit and reducing the frequency of sessions needed.

Alzheimer’s prevention. The Harvard 2025 study (Aron et al., 2025) found that lithium depletion in the brain is an early event in Alzheimer’s pathogenesis, that GSK3β activation drives amyloid and tau accumulation, and that lithium orotate reversed these changes in mice. Lithium orotate for neuroprotection in aging is a separate and significant application that is likely to be studied in clinical trials in the near future.

What Lithium Orotate Does Not Do

Lithium orotate is not a psychedelic. It does not produce altered states of consciousness, visual changes, emotional catharsis, or mystical experiences. The psychedelic experience itself may have independent therapeutic value — ego dissolution, perspective shifts, emotional processing — that GSK3β inhibition alone does not provide. Some patients may need the full psychedelic experience for trauma processing or perspective change. Lithium orotate would not replace this.

Lithium orotate at supplement doses is not a treatment for acute mania, psychosis, or severe bipolar I disorder. These conditions may require the higher brain lithium levels achievable with prescription lithium carbonate at therapeutic doses.

Lithium orotate is not proven effective for depression in humans through randomized controlled trials. The mechanistic argument is strong and the convergent evidence from four pharmacologically distinct GSK3β inhibitors is compelling, but direct clinical evidence for lithium orotate specifically for depression does not yet exist. The Harvard 2025 study was in mice for Alzheimer’s. Extrapolation to human depression is a hypothesis, not an established fact.

The Practical Protocol

Based on clinical experience from practitioners who prescribe lithium orotate (Greenblatt, Emmons, and others), user reports, and the mechanistic reasoning above:

Starting dose: 5mg lithium orotate taken at night before bed.

Titration: If no side effects after one week, increase to 10mg. If still no side effects after another week, increase to 15-20mg. Maximum supplement dose: 20mg.

Timing: Before bed. The acute GSK3β inhibition peaks approximately 2 hours after dosing. Taking it at night means the peak inhibition occurs during sleep, when synaptic remodeling and spine stabilization are most active. Any transient brain fog from the glutamate modulation occurs during sleep rather than during the day.

What to monitor: Water retention (the most common side effect at supplement doses), thyroid function (prudent to check TSH after 3 months of daily use), and morning clarity (the primary outcome measure — do you feel different before coffee?).

Duration: Unknown. For burnout recovery, a 4-6 week loading period may be sufficient if the structural gains (spine regrowth, GR priming) persist after cessation. For FKBP5 T-allele carriers with permanently elevated thresholds, ongoing daily supplementation may be necessary. For seasonal depression, seasonal use (September through April) may be appropriate. These are hypotheses, not established protocols.

Combination with alcohol: Moderate alcohol raises BDNF in the dorsolateral striatum through a RACK1-mediated pathway that is mechanistically distinct from lithium’s CREB-mediated BDNF pathway. However, alcohol acutely activates GSK3β — the opposite of lithium’s effect. Lithium may partially buffer against alcohol’s GSK3β activation, reducing the molecular cost of each drink. The combination is not contraindicated at supplement lithium doses. (See FKBP5.com for the full alcohol-BDNF analysis.)

Proposed Studies

1. Lithium orotate for treatment-resistant depression. Randomize patients with treatment-resistant MDD to lithium orotate (10-20mg/day) versus placebo for 8 weeks. Measure depression scores, GSK3β phosphorylation in peripheral blood mononuclear cells (as a proxy for brain GSK3β status), and serum BDNF. Prediction: lithium orotate group will show significant improvement in depression scores with increased GSK3β Ser9 phosphorylation and BDNF levels.

2. Lithium orotate as post-ketamine maintenance. Randomize ketamine responders to lithium orotate (10-20mg/day) versus placebo following their final infusion. Measure time to relapse. Prediction: lithium orotate group will show significantly longer duration of benefit, as daily GSK3β inhibition maintains the synaptic gains produced by the ketamine series.

3. Lithium orotate for seasonal affective disorder. Randomize SAD patients to lithium orotate (10-20mg/day) versus placebo beginning in September, before symptom onset. Measure depression scores monthly through March. Prediction: lithium orotate group will show attenuated winter symptom severity, as direct GSK3β inhibition compensates for reduced photoperiod-driven cortisol-GR-GSK3β suppression.

4. GSK3β phosphorylation as a biomarker of psychedelic response. Measure GSK3β Ser9 phosphorylation in peripheral blood before and after ketamine, psilocybin, and MDMA administration. Prediction: all three substances will produce increased Ser9 phosphorylation, and the degree of phosphorylation will correlate with clinical response, confirming GSK3β as the convergent target.

5. Lithium orotate versus lithium carbonate for brain delivery. Replicate the Aron et al. (2025) finding in humans using MRI spectroscopy to measure brain lithium concentrations following equivalent elemental lithium doses of orotate versus carbonate. Prediction: orotate will achieve higher brain concentrations at lower serum levels, confirming superior blood-brain barrier penetration in humans.

6. GSK3β genotyping and depression treatment response. Genotype depressed patients for GSK3β-related polymorphisms and assess treatment response to SSRIs versus lithium. Prediction: patients with variants associated with higher baseline GSK3β activity will show preferential response to lithium (direct GSK3β inhibitor) over SSRIs (which affect GSK3β indirectly and incompletely).

7. Insulin resistance as a predictor of GSK3β-mediated depression. Measure HOMA-IR (insulin resistance index) in depressed patients and correlate with response to GSK3β inhibitors (lithium, ketamine) versus monoamine-targeted drugs (SSRIs). Prediction: insulin-resistant depressed patients will show preferential response to GSK3β inhibitors, because their depression is driven partly by insufficient insulin-mediated GSK3β suppression. This would also predict that metformin or other insulin sensitizers should have antidepressant effects specifically in the insulin-resistant subpopulation — a prediction that can be tested in existing metformin trial datasets.

The Bigger Picture

The psychiatric establishment classifies depression as a serotonin problem, a dopamine problem, a glutamate problem, or a neuroplasticity problem depending on which department you ask. Each classification spawns its own treatment paradigm, its own clinical trials, and its own pharmaceutical industry. SSRIs for the serotonin model. Stimulants for the dopamine model. Ketamine clinics for the glutamate model. Psychedelic retreat centers for the neuroplasticity model.

What if they are all downstream of the same upstream target?

GSK3β sits at the convergence point. Serotonin suppresses it through 5-HT → Akt. Dopamine modulates it through D2 → Akt. Glutamate regulates it through NMDA → AMPA → Akt. Cortisol suppresses it through GR → PI3K → Akt. BDNF suppresses it through TrkB → PI3K → Akt. Every major neurotransmitter system implicated in depression feeds into the same kinase.

This does not mean GSK3β is the “cause” of depression. Depression has many causes — trauma, loss, inflammation, hormonal disruption, chronic stress, genetic vulnerability. But these diverse causes may converge on a shared molecular endpoint: overactive GSK3β producing synaptic degradation in circuits that maintain mood, motivation, and the subjective sense that life is worth living.

If this is correct, then the treatment question simplifies dramatically. Instead of trying to determine which upstream neurotransmitter system is dysfunctional in each individual patient — a task that has proven nearly impossible after decades of trying — clinicians could target the convergent endpoint directly.

The most accessible, sustainable, and safest way to do this is lithium orotate.

A $12 bottle. No prescription. No trip. No clinic. Taken before bed.

The most important psychiatric drug of the 21st century might already be on Amazon.

Key References

Aron, L. et al. (2025). Lithium deficiency and the onset of Alzheimer’s disease. Nature, 645(8081), 712-721.

Beurel, E., Song, L. & Jope, R.S. (2011). Inhibition of glycogen synthase kinase-3 is necessary for the rapid antidepressant effect of ketamine in mice. Molecular Psychiatry, 16(11), 1068-1070.

Jeanneteau, F. et al. (2015). BDNF and glucocorticoids regulate corticotrophin-releasing hormone (CRH) homeostasis in the hypothalamus. Proceedings of the National Academy of Sciences, 109(4), 1305-1310.

Jope, R.S. (2003). Lithium and GSK-3: one inhibitor, two inhibitory actions, multiple outcomes. Trends in Pharmacological Sciences, 24(9), 441-443.

Nardou, R. et al. (2019). Oxytocin-dependent reopening of a social reward learning critical period with MDMA. Nature, 569, 116-120.

Polter, A. et al. (2010). Deficiency in the inhibitory serine-phosphorylation of glycogen synthase kinase-3 increases sensitivity to mood disturbances. Neuropsychopharmacology, 35(8), 1761-1774.

Liu, E. et al. (2017). GSK-3β deletion in dentate gyrus excitatory neuron impairs synaptic plasticity and memory. Scientific Reports, 7, 5781.

Ochs, S.M. et al. (2015). Loss of neuronal GSK3β reduces dendritic spine stability and attenuates excitatory synaptic transmission via β-catenin. Molecular Psychiatry, 20, 482-489.

This paper is a mechanistic hypothesis, not medical advice. Lithium orotate has not been evaluated by the FDA for the treatment of depression. Consult a healthcare provider before starting any supplement, particularly if you are taking psychiatric medications.

For the upstream genotype model explaining why some individuals are particularly vulnerable to GSK3β overactivation, see FKBP5.com.

The author is not a physician or neuroscientist. She is a software engineer, an FKBP5 rs1360780 T/T carrier, and a person who noticed that four different substances made the world feel brighter and wanted to know why.