Early or Heavy Cannabis Use Dampens Motivation
Research has already discovered that people who abuse substances such as cocaine or amphetamine have altered dopamine systems.
Now a new study done at Imperial College London, UCL, and King’s College London shows the same is true for those who start using cannabis at an early age or who are heavy cannabis smokers.
Using brain imaging technology, researchers looked at the brains of 19 regular marijuana smokers and 19 non-users, matched for age and sex. They found that dopamine levels were lower in an area of the brain called the striatum if the smokers started their habit between the ages of 12 and 18 or used heavily.
All of the study participants who were users had experienced psychotic-like symptoms while smoking – some reported feeling threatened by unknown forces, and others experienced “strange sensations.” Because dopamine production is associated with psychosis, it was thought that dopamine levels would be high in these individuals, but the opposite proved true.
Dopamine and Our Mind-Body Health
Dopamine is one of our brain’s neurotransmitters. Its job is to transmit messages or signals from one neuron (brain nerve cell) to another. Dopamine is produced in different parts of the brain and has several functions. It plays a role in attention, mood, sleep, thinking, motivation, learning, working memory and voluntary movement. Dopamine dysfunction has been linked to ADHD, Parkinson’s disease and schizophrenia.
Studies have revealed that our body releases dopamine when we obtain a reward or something that satisfies us, and it also encourages us to achieve good things or avoid the negative. Dopamine levels vary from person to person, so some of us are more persistent than others at reaching for our goals. It could also be that high levels of dopamine cause some people to be sensation-seekers; they might pursue gambling or abuse drugs.
In the London study, the low levels of dopamine found in the brain’s striatum may explain the apparent but unproven “amotivational syndrome” associated with cannabis users. Long-term and heavy users often seem to lack the motivation to work or pursue their interests. It has yet to be determined if this motivation-dampening effect of marijuana is reversible, but some studies suggest it may be.
Whether the possibility of diminishing the body’s supply of dopamine deters a person from smoking pot is naturally a personal preference. Life is difficult enough without crimping our chemical reserves of motivation with drugs, but the pleasure of smoking pot often outweighs the risks.
However, this research may help in the diagnosing of marijuana addiction. Those users in the London study who had the lowest levels of dopamine met the standard diagnostic criteria for cannabis abuse or dependence. Scientists think that eventually, dopamine levels might be used to measure the severity of a person’s addiction.