What is dopamine?
Dopamine is a neurotransmitter in the brain that regulates functions such as movement, motivation, reward, and pleasure. It plays a crucial role in the brain's reward and pleasure systems, as well as in processes like attention, mood, learning, and memory. Dopamine helps to regulate the flow of information, allowing what is important to stand out and irrelevant distractions to be suppressed.
Despite the frequent reference to fluctuating dopamine levels when one completes an enjoyable task or when one is in a slump, the total amount of dopamine in the brain remains relatively stable. It is instead the dopamine signalling between brain cells that can be altered or disrupted.
What is dopamine signalling?
Dopamine signalling is what enables dopamine as a messenger to move from one neuron, or area of the brain, to another. Key brain regions influence dopamine signalling in parts of the brain depending on the understanding of the individual's environment. For example, if an individual feels they are in a hazardous environment, then there will be more dopamine signalling in the threat detection centres of the brain.
Think of your dog that has developed a strong anticipation for when you will arrive home from work. Around 6 pm your dog’s dopamine signalling will increase in the reward processing parts of its brain as it anticipates your arrival, thus readying itself for movement and perhaps to digest a snack.
Dopamine Signalling in Paranoid Schizophrenia
Among individuals with paranoid schizophrenia (PSZ), there is believed to be an excess of dopamine signalling in specific brain areas associated with auditory and visual processing. The excessive dopamine signalling in brain regions associated with dopamine signalling causes individuals with PSZ to perceive peripheral stimuli as more important or significant to them. For instance, while a neurotypical person may hear a distant door slam and dismiss it as irrelevant, a person with PSZ may perceive it as personally relevant, creating a narrative between the door slam and themselves (i.e., ‘someone is annoyed with me’, or ‘someone is rushing out of their house to come and confront me’).
The heightened dopamine signalling in these brain areas manifests in an increased awareness of stimuli in one’s environment, a belief that the stimuli are important and relevant to oneself which leads to paranoia. Individuals may then experience heightened alertness, suspiciousness, and a sense of persecution or conspiracy as the excessive stimuli in their environment appear to be threatening them.
Dopamine Signalling in ADHD
In contrast, those with ADHD are found to have low dopamine signalling in areas associated with attention, working memory, and impulse control. Dopamine is crucial for regulating attention and focus by modulating brain circuits involved in attentional processes. Lower dopamine signalling can lead to difficulties in filtering out distractions, maintaining focus, and sustaining attention, which are characteristic symptoms of conditions like attention deficit hyperactivity disorder (ADHD). Individuals with ADHD may appear inattentive, easily distracted, and have difficulty staying on task; often showing attentiveness to only highly stimulating sensory information.
Why is this relevant to me?
Understanding brain chemistry is helpful for being more empathetic towards ourselves and those struggling with particular mental health conditions. Though you may not have schizophrenia or ADHD, understanding dopamine and dopamine signalling can provide insight into how our brains work and vary in the processing of external stimuli.
In the modern day, overactive dopamine signalling is a common issue. Whereas spending time scrolling on social media or bingeing TV spikes dopamine signalling, practising mindfulness, yoga, engaging in creative pursuits or listening to calming music reduces dopamine signalling. The more our lives revolve around activities promoting high dopamine signalling with an absence of those that reduce it the more we enslave ourselves to the self-fulfilling nature of constantly seeking dopamine and feeling deeply unoccupied without it. As a parting thought, consider the impact of dopamine signalling in this new age of working from home, and keeping our phones nearby at all times.