Dopamine and serotonin are the sought-after 'happy hormones' celebrated for their mood-boosting powers. But, while the perks are undeniable, too much of one can quickly wipe away your smile.

Serotonin and dopamine are often bundled together as a duo of powerful neurotransmitters that spark positive emotion. But, to the surprise of many, dopamine and serotonin do not go hand-in-hand. Pediatric endocrinologist Robert Lustig, says the key to this lies in the fact that dopamine and serotonin are two different bio-chemicals, two different neuro-transmitters, in two different areas of the brain.

Serotonin is associated with feelings of happiness, focus and calmness. Dopamine is more aligned to feelings of reward and motivation. When you get a quick dopamine hit it creates a rush of pleasure. If feels good. But it doesn't last long. Which is where the issues can come in. Having high doses of dopamine concentrated in specific areas of the brain is linked to being overly competitive, aggressive and having a lack of impulse control. It’s been associated with ADHD, binge eating and addiction, as well as mental health conditions and mood disorders.

Dopamine is what is called an ‘excitatory’ neurotransmitter, says Lustig, who explains that neurons like to be ‘tickled’ but they don’t like to be bludgeoned. And if they are overstimulated, it can cause neuronal cell death. When the neuron dies, the neuron next to it will trigger a self-defence mechanism to down-regulate the receptors for dopamine, so that it too won't die. As a result, you get a rush, but because the receptors go down, next time you have fewer receptors, so you need a bigger hit to get the same rush. This goes on until even a huge hit has no effect. “That’s called tolerance. And when the neurons start to die, that’s called addiction,” says Lustig

Serotonin does not behave this way because it is an ‘inhibitor’. “It doesn’t cause the next nerve to fire,” says Lustig, “it causes the next neuron to stay silent. You can’t overdose on happiness.” However, there is one thing that can down-regulate serotonin – dopamine. “So the more pleasure you seek, the more unhappy you get.”

“You can’t overdose on happiness … but the more pleasure you seek, the more unhappy you get.”

The complex relationship between serotonin and dopamine is why addiction and depression are different sides of the same coin. “Addiction is from too much dopamine driving down the receptor and then the neurons die. Depression is serotonin deficiency – too little serotonin, which has been driven by dopamine.


Being able to identify the difference between happiness and pleasure is key to enjoying a life of long-term health and well-being.

Pleasure is short-lived, visceral, can be experienced alone, and can be caused by substances or behaviors.

Happiness is long-lived, ethereal, usually social, and cannot be had from substances or behaviors.

Curbing dopamine-driven compulsiveness

Drugs, mobile phones, social media, fast food, coffee, gambling and even shopping all have a similar, short-term but highly compulsive effect on human behavior. They spark that rush of dopamine. (Exercise also stimulates the same effect. But in most cases, a compulsion to do more exercise is a good thing.)

The fast food industry is a great example of companies taking advantage of the little hitch in our biochemistry and tapping into the neural science of our brains. These companies have become adept at peddling substances (sugar and caffeine) that directly affect the reward center of the brain. The fact that fast food and soft drinks are ‘price inelastic’ – meaning, even when prices rise, demand stays the same – is a sign addiction is at play, says Lustig.

"We have the data, we have the neuroscience, we have the imaging studies, we have the biochemistry to demonstrate how the food industry has basically doctored our food supply so as to make it absolutely irresistible, and in the process, we have gotten sick."

Compounding the problem, a chemical in the gut needed to make serotonin – tryptophan – is not found in processed food. Tryptophan is the rarest amino acid in our diet, found in eggs, fish and some poultry – three items rare in processed food.

"People eating a highly processed food diet probably are not even getting the precursor to make the serotonin in the first place, so that is a great reason for unhappiness."

Lustig says he has a simple, evidence-based, four-step process to combat this problem.

To tamp down the dopamine and up the serotonin, focus on the Four Cs – Connect, Contribute, Cope and Cook.


Connect: Catch up with a friend, spend time with your loved ones, and take time to connect with yourself, practice your religion or spiritual practice if that's your thing. Spending time with animals is also restorative. Lustig has a hypothesis that workplace pets (when done properly) may spark higher serotonin levels across the team, which boosts individual morale and team cohesion.

Contribute: Make time to contribute to something bigger than yourself. Look for opportunities to use your time and energy to make the world a better place.

Cope: Take action to look after your body. Get sufficient sleep, calm your mind with mindful activities like meditation and yoga, and move your body with regular exercise.

Cook: Eat a well-balanced healthy diet and importantly limit the foods and additives that degrade your body and mind.

Dr Robert Lustig is the author of The Hacking of the American Mind: The Science Behind the Corporate Takeover of Our Bodies and Brains.

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