A dopamine cocktail

Our brain is what makes us human. It is a vast network of connections that enable us to perform everything from the simplest actions, such as walking, to complex and abstract processes, such as imagining.

These functions rely on neural communications, for which our nervous system uses molecules called neurotransmitters. There are many types, and one of the most important is dopamine, which is the substance associated with the production of pleasure and happiness. It is the neurotransmitter most used by the brain, and both its excess and absence are associated with mental and neurological illnesses.

We all need an adequate level of dopamine, but not only that, we also need it to be distributed properly throughout the brain to enable us to carry out many functions: it drives us to be competitive, to develop a sense of self-preservation in the face of danger, and to motivate ourselves to achieve personal goals. It influences our mood and behaviour, and is essential for regulating metabolism. It is considered the 'pleasure' neurotransmitter and plays a key role in courtship, sexuality and desire.

There are other main functions in which dopamine is the main factor:

• Personal satisfaction: various studies have found that a person who feels satisfied with their life and maintains a high level of self-esteem has a greater number of dopamine D2 receptors in the brain.
• Thrill seeking: neuroscience has found that a person with more dopamine in certain brain regions is more likely to seek thrills and take risks, for example, through extreme sports.
• Overweight and obesity: not everyone feels the same level of pleasure when eating chocolate. People who are prone to being overweight have fewer dopamine receptors in their nervous system and, therefore, need to eat more chocolate to feel a similar level of satisfaction to others who have higher levels of dopamine in their brain.
• Drug use: because dopamine is linked to pleasure or satisfaction, a drug addiction can result in low dopamine levels. When a drug, such as cocaine, is taken, it binds to the dopamine transporter protein and blocks the normal recycling process, thus exaggerating the drug's pleasurable effects.
• Creativity: people who are more creative have fewer D2 dopamine receptors in the thalamus. The main role of this part of the brain is to filter stimuli before they reach the cerebral cortex. If the thalamus has fewer dopamine receptors, it filters fewer signals. This means that more information flows from the thalamus, thus increasing the neural connections that help with the association of concepts, thereby improving creativity.
• Memory regulation: Dopamine is responsible for regulating the duration of information, or rather, memories. When we learn something that satisfies us or gives us pleasure, dopamine activates the hippocampus to retain this information; conversely, when the memory is not satisfying or interesting, dopamine does not activate the hippocampus and the memory is not stored.
• Levels of motivation: people who achieve very demanding goals have been found to have higher levels of dopamine in their brains, thus confirming the link between dopamine and motivation.
• Individual personality: dopamine could be a factor in determining whether a person is more introverted or extroverted, cowardly or brave, confident or insecure.

Furthermore, when we are in love, we experience pleasurable and satisfying emotions. The chemical process of love involves the release of dopamine, serotonin and oxytocin.

Low levels of dopamine are also associated with problems with socialising, and high levels are linked to hyperactivity, hypersexuality, and hypersocialisation.

When dopamine is abnormally high, it is associated with psychosis and schizophrenia. Drugs such as amphetamine and cocaine, which are known to significantly increase dopamine levels, can cause psychosis. For this reason, most modern antipsychotic drugs are designed to block dopamine function to varying degrees.

There are also disorders related to the poor distribution of dopamine, such as Parkinson's disease or ADHD (Attention Deficit Hyperactivity Disorder).