The Brain Chemistry Map

How your brain's chemicals shape attention, mood, memory & focus — and the supplements that support each system. A single-page guide.

The Big Idea: Accelerators, Brakes & Dials

Every mental state is a balance — not one chemical, but a ratio between several. Two chemicals set your baseline excitability; the rest tune specific circuits on top.

⚡ Accelerator

Glutamate — the brain's main excitatory signal. Drives learning and the synaptic strengthening that encodes memory.

🛑 Brake

GABA — the main inhibitory signal. Quiets neural activity to produce calm and reduce anxiety.

🎛️ Dials & Climate

Dopamine, serotonin, etc. tune specific circuits. Hormones like cortisol set the overall emotional weather.

Baseline set by Glutamate ⇄ GABA  →  tuned by dopamine · norepinephrine · serotonin · acetylcholine  →  shaped by cortisol · oxytocin · BDNF  →  your mental state

The Chemicals

The core neurotransmitters and modulators. Notice that most work on an inverted-U — too little and too much both cause problems.

Accelerator (excitatory) Brake (inhibitory) Dial (circuit tuner) Modulator / hormone

Dopamine

Dial
Motivation · Focus · Reward · Drive

Less about pleasure, more about wanting and pursuing. Powers goal-directed focus, working memory and movement.

Too littleapathy, poor focus, low drive
Too muchimpulsivity, addiction, mania

Norepinephrine

Dial
Alertness · Attention · Arousal

Your "vigilance and engagement" chemical. Sharpens attention and drives fight-or-flight with adrenaline.

Too littleinattention, fatigue, brain fog
Too muchanxiety, racing thoughts

Serotonin

Dial
Mood · Calm · Contentment

Governs mood stability, sleep, appetite and a sense of "enough." ~90% is made in the gut.

Too littledepression, anxiety, impulsivity
Too muchserotonin syndrome (rare)

GABA

Brake
Calm · Relaxation · Anti-anxiety

The brain's main inhibitory signal. Target of alcohol, benzodiazepines and many sleep aids.

Too littleanxiety, restlessness, insomnia
Too muchsedation, sluggishness

Glutamate

Accelerator
Learning · Memory encoding

The main excitatory signal and workhorse of learning. Drives the synaptic strengthening that stores memories.

Too littlepoor learning, low cognition
Too muchexcitotoxicity, seizures

Acetylcholine

Dial
Memory · Learning · Attention

Most tied to memory sharpness and forming new memories. Its decline is central to Alzheimer's.

Too littlememory loss, poor focus
Too muchcramps, over-arousal

Cortisol

Hormone
Stress response

Useful in short bursts. Chronically high cortisol shrinks the hippocampus, impairs memory and fuels anxiety.

Too littlefatigue, low blood pressure
Too muchmemory loss, anxiety, poor sleep

BDNF

Growth factor
Neuroplasticity · "Brain fertilizer"

Promotes neuron growth, survival and rewiring. The keystone of long-term learning, mood and resilience.

Lowrigidity, decline, low mood
Highsharp learning & resilience

Oxytocin

Hormone
Bonding · Trust · Social calm

Released through connection, touch and trust. Lowers stress and anxiety and builds social safety.

Lowisolation, higher stress
Hightrust, calm, connection

Endorphins

Modulator
Pain relief · Natural high

Your internal opioids. Released by exercise, laughter and stress — the source of the "runner's high."

Lowmore pain, low mood
Higheuphoria, pain relief

Melatonin

Hormone
Sleep timing

Sets your sleep clock — which indirectly governs memory consolidation and overnight clearing of brain waste.

Lowpoor sleep, disrupted rhythm
Highdrowsiness, grogginess
Function Map

The states you asked about, and the chemical mix behind each. ▲ higher, ▼ lower, ● key player.

🎯 Attention & Focus

The "focus trio," balanced. Too little and you can't engage; too much norepinephrine tips focus into anxiety.
DopamineNorepinephrineAcetylcholine

😰 Anxiety

An over-excited, under-braked brain — too little brake, too much stress signalling.
GABA ▼Norepinephrine ▲Cortisol ▲Serotonin

🌧️ Depression

A whole-system state, not just "low serotonin" — add low BDNF, chronic cortisol and inflammation.
Serotonin ▼Dopamine ▼BDNF ▼Cortisol ▲

🧠 Memory Strength

Encoding + formation + plasticity, with dopamine tagging what matters. Cortisol is the enemy.
GlutamateAcetylcholineBDNFCortisol ▼

Cognitive Health & "Smartness"

Not any single chemical — the health of the whole system: strong plasticity, balance, low chronic stress.
BDNF ▲Balanced neurotransmittersCortisol ▼

😌 Calm & Stability

A well-braked, contented baseline — the brake engaged and the emotional climate warm.
GABA ▲SerotoninOxytocin ▲Cortisol ▼
Supplements by System

What can support each system — colour-coded by honest evidence tier. Filter below. This is educational, not medical advice.

Show all 🟢 Solid evidence 🟡 Decent / situational 🟣 Promising / hyped 🔴 Doctor-only

Foundational — fix these first (biggest proven impact)

Omega-3 (EPA/DHA)Solid

Neuronal membranes, mood, memory.

Vitamin DSolid

Mood & cognition; deficiency is common.

MagnesiumSolid

Glycinate/threonate — calm, sleep, memory.

B vitamins (B6/B9/B12)Solid

Cofactors for making every neurotransmitter.

Iron & ZincSolid

Needed for dopamine synthesis.

Dopamine — motivation & drive

L-TyrosineDecent

Precursor; helps focus under stress.

Rhodiola RoseaDecent

Adaptogen; drive, less fatigue.

CaffeineSolid

Boosts dopamine signalling & alertness.

Stimulants / L-DOPARx

Powerful; doctor-supervised only.

Norepinephrine — alertness & attention

Caffeine + L-TheanineSolid

The classic stack: calm, jitter-free focus.

AtomoxetineRx

Norepinephrine drug for ADHD.

Serotonin — mood & contentment

5-HTP / TryptophanDecent

Precursors. Don't mix with antidepressants.

Saffron extractDecent

Surprisingly good for mild low mood.

St. John's WortRx-caution

Works, but major drug interactions.

SSRIs / SNRIsRx

Frontline prescription antidepressants.

GABA — calm, anti-anxiety, sleep

AshwagandhaSolid

Good evidence for lowering stress & cortisol.

L-TheanineSolid

Relaxed alertness.

Glycine / TaurineDecent

Support calm & sleep.

BenzodiazepinesRx

Effective but habit-forming; short-term only.

Acetylcholine — memory & learning

Citicoline / Alpha-GPCDecent

Raise acetylcholine; cognitive support.

Bacopa MonnieriDecent

Improves memory over weeks of use.

Lion's ManeEarly

May support nerve growth factor.

Huperzine ARx-caution

Potent — cycle, don't use daily.

BDNF & neuroplasticity — long-term brain health

CreatineSolid

Cheap, safe; helps under stress/sleep loss.

Omega-3Solid

Supports plasticity & mood.

CurcuminEarly

Needs a bioavailable form.

Lion's ManeEarly

Promising for nerve growth.

Cortisol / stress regulation

AshwagandhaSolid

Best-evidenced for chronic stress.

RhodiolaDecent

Adaptogen for stress & fatigue.

MagnesiumSolid

Supports a calmer stress response.

Classic "nootropics" (cognition-specific)

RacetamsEarly

Decades of use, mixed evidence.

NoopeptEarly

Stronger, less studied.

Ginkgo BilobaDecent

Circulation/memory, modest effect.

Panax GinsengDecent

Mild cognitive & energy support.

Safety Principles
  • Fix the foundation first. Sleep, exercise, stress, nutrition and connection move every chemical at once — more than any pill.
  • Add one thing at a time so you actually know what's working.
  • More is not better. Many follow an inverted-U — too much backfires (tyrosine, huperzine).
  • Don't stack serotonergics. Never combine 5-HTP or St. John's Wort with prescribed antidepressants — serotonin syndrome risk.
  • Check interactions if you take any prescription — especially antidepressants, blood thinners or blood-pressure drugs.
  • Behaviour beats supplements for cortisol and BDNF. Pills are the smaller lever.

Disclaimer: This is an educational summary, not medical advice. Evidence quality varies and individual needs differ. Talk to a physician before starting anything beyond basic nutrients — especially if you take other medications.