Substance Misuse and Mental Health

Our thoughts, feelings and behaviour are controlled by a complex messenger system made of chemicals called neurotransmitters. These neurotransmitters are sensitive to what is going on in our internal and external environment and will react and guide us in our response.

One particular chemical neurotransmitter, dopamine, is released when we partake in pleasurable activities and creates strong memories of that positive feeling. Research has found that the most commonly addictive psychoactive substances are the ones that have influence on the dopamine system.

Drugs impact our neurotransmitters by imitating, stimulating or prolonging their effect. Methamphetamine, for example, increases the amount of dopamine within our system, artificially generating the feeling of being ‘high’. The interaction also stimulates the creation of memories of the euphoria, thus leading to people seeking the experience again.

By introducing drugs into our body, our natural balance of chemicals and the messenger systems are disrupted. Our brain, in an attempt to re-establish the appropriate levels of chemicals within our system, may reduce the number of neurotransmitters, as well as their receptors. This impacts our ability to achieve that feeling of pleasure that we crave and, as a result, people will often increase the dosage to obtain a ‘high’ that the body is no longer capable of achieving.

By understanding the influence substances have upon the different chemical messenger systems within our body, we can start to understand the nature and true impact of addiction.