Dopamine is the most popular of neurotransmitters. Forget about the unsung heroes of neurotransmission glutamate and GABA (ever heard of them?), dopamine is the one most people have heard of. It’s the current click-bait of popular neuroscience and seems to be the darling of newspaper editors looking for something to make their science pages a bit more ‘sexy' or ‘controversial'.
Take this article from the Daily Mail which claims power corrupts because of activation of dopamine pathways relative to social hierarchy in baboons. Perhaps the editors at the Daily Mail are imagining cocaine-fuelled parties on the African savannah?
Or this one, from the bastion of British investigative journalism, The Sun, which contends that having people like your pictures on Facebook is addictive because … you guessed it, dopamine.
And more recently an article from the New York Post went viral and claimed that iPads are turning children across the globe into ‘psychotic junkies’ because of … dopamine.
Here is the important thing to remember: just because an experience we enjoy ‘triggers release of dopamine’, or ‘activates reward pathways’, this does not mean that the experience in and of itself is ‘addictive’ or is ‘like a drug'. The truth, like most things in neuroscience, is far more nuanced and wonderful!
Dopamine: a rewarding molecule
Dopamine is a neurotransmitter. Neurotransmitters allow neurons to communicate and are signalling molecules released at synapses by spikes of electrical activity. When dopamine is released it diffuses across the synapse and binds to receptors in the membrane of the post-synaptic neuron. In doing so, dopamine signals a diverse range of actions that range from controlling movement, to releasing breast-milk, to decision-making and feelings of pleasure.
Surprisingly, only a very small number of neurons (about half a million of 100 billion, or so) produce dopamine. These dopaminergic neurons reside deep in the midbrain and send axons to the prefrontal cortex thus forming part of the mesolimbic pathway, or reward pathway. And this is the region that attracts the most attention.
To understand the role of dopamine in pleasure, reward, motivation and addiction, we need to take a step back and consider why we seek some experiences out. Neuroscience writer Mo Costandi explains,
“Our bodies’ internal needs motivate our behaviour in certain directions, leading us to specific goals that fulfil these needs. Hunger motivates us to get food; thirst motivates us to find water; and feeling cold motivates us to seek warmth. Eating and drinking are essential for our survival, and we experience them as being rewarding and pleasurable, so we have a natural urge to repeat the behaviours that enable us to obtain them. Sexual behaviour and raising children are similarly pleasurable, because they ensure our long-term survival….”
The release of dopamine in the brain’s reward pathways assigns value or status to each type of reward, and this will determine the length we go to achieve a given reward, or pleasurable experience.
“All pleasurable activities cause midbrain neurons to release dopamine … all of this reinforces the behavioural patterns that lead to obtaining the reward, make us more likely to repeat them in the future.”
Does dopamine release = addiction?
Addiction is a highly complex process that involves the interplay between a chemical or behaviour, genetics, learning, and the environment. Some addictive drugs (e.g. cocaine, amphetamines, and nicotine) hijack the brain’s reward mechanisms by directly influencing how dopamine is released, binds to dopamine receptors, or is mopped up.
Prolonged exposure to many additive drugs eventually suppresses activity in the neural reward pathways leading to tolerance (more of the drug is needed to get the same effect).
It’s absolutely true that substances such as cocaine or heroin massively enhance dopamine transmission. BUT this does not mean that everything that triggers dopamine release is addictive. This is a logic fallacy.
Yes, dopamine has a role in addiction and plays a major role in reward and pleasure, but to say it 'causes' addiction misses all the other biological, psychological and sociological influencing factors.
Dopamine and ‘digital addiction'.
The latest scaremongering headline from the New York Post would have you think that children who are engaged in video games show similar patterns of addition as heroin users. The article ‘It’s ‘digital heroin’: How screens turn kids into psychotic junkies‘ contained the following emotive statement,
“We now know that those iPads, smartphones and Xboxes are a form of digital drug. Recent brain imaging research is showing that they affect the brain’s frontal cortex — which controls executive functioning, including impulse control — in exactly the same way that cocaine does. Technology is so hyper-arousing that it raises dopamine levels — the feel-good neurotransmitter most involved in the addiction dynamic — as much as sex.”
From a neuroscience perspective this is complete RUBBISH.
Yes, both Minecraft and cocaine both activate the dopaminergic reward pathway in the brain, but this does NOT mean kids who enjoy Minecraft are ‘addicted' ‘psychotic junkies'!! Dopamine does not equal addiction!
As we mentioned above, dopamine is released in mesolimbic pathway during numerous pleasurable or rewarding experiences: when you're having sex, cuddling your kids, quenching your thirst with a glass of water, shopping, watching Netflix, having a hot bath, and even … eating sugar (but let's leave the sugar=cocaine story for another rant).
This doesn't mean everything enjoyable and rewarding is like a ‘drug' and that highly engaging dopamine-triggering activities put you or kids on the slippery slope to addiction. You'll never see a newspaper headline warning that the feeling you get drinking water to quench your thirst is the same as a hit of heroin.
Technology is NOT a drug, it's a tool (and its here to stay). We need to teach kids how to use it wisely, rather like driving a car.
The New York Post's sloppy, ‘fear-reviewed' report incited panic, cherry-picked the neuroscience, and missed the nuance and potential of technology to help as well as harm (and showed a clear misunderstanding of dopamine!!).
Instead I suggest you read this piece explaining in more detail why its neuro-garbage, this article for a backgrounder on dopamine, and check out this excellent blog by Jocelyn Brewer on the concept of digital nutrition. Jocelyn wisely says,
Using the word addiction in this conversation stigmatises technology users and the challenges facing parents and educators to effectively integrate technology into both leisure and learning in a balanced way that is tailored to the needs of individuals.
Labelling a generation of kids as addicted to screens and stereotyping them invariably as rude, disrespectful, disconnected and mute is both mean and myopic.
Ignoring the fact that adults are responsible for technology being in their hands is parochial. The issue here is that kids appear to enjoy and engage with technology more than their parents. Adults generally have forgotten how to be curious and playful and haven’t thought to ask why. The nuances of online worlds escape most ‘digital xenophobes’ (those who fear technology because they don’t understand it).
One final note, hopefully reading this blog has triggered a bit of dopamine release and you'll come back to read the next one!
This blog was penned by my contributing writer Dr Olivia Hibbitt. Olivia is a kiwi neuroscientist and medical writer who settled here in Sydney after a stint conducted research at Oxford University. You can connect with her via LinkedIn.
Read more about this at yourbrainhealth.com.au.