Ancestry, Cannabis

Genetic Variations in the Human Cannabinoid Receptor Gene Are Associated with Happiness

Abstract

Happiness has been viewed as a temporary emotional state (e.g., pleasure) and a relatively stable state of being happy (subjective happiness level).

As previous studies demonstrated that individuals with high subjective happiness level rated their current affective states more positively when they experience positive events, these two aspects of happiness are interrelated.

According to a recent neuroimaging study, the cytosine to thymine single-nucleotide polymorphism of the human cannabinoid receptor 1 gene is associated with sensitivity to positive emotional stimuli.

Thus, we hypothesized that our genetic traits, such as the human cannabinoid receptor 1 genotypes, are closely related to the two aspects of happiness.

In Experiment 1, 198 healthy volunteers were used to compare the subjective happiness level between cytosine allele carriers and thymine-thymine carriers of the human cannabinoid receptor 1 gene.

In Experiment 2, we used positron emission tomography with 20 healthy participants to compare the brain responses to positive emotional stimuli of cytosine allele carriers to that of thymine-thymine carriers.

Compared to thymine-thymine carriers, cytosine allele carriers have a higher subjective happiness level. Regression analysis indicated that the cytosine allele is significantly associated with subjective happiness level.

The positive mood after watching a positive film was significantly higher for the cytosine allele carriers compared to the thymine-thymine carriers.

Positive emotion-related brain region such as the medial prefrontal cortex was significantly activated when the cytosine allele carriers watched the positive film compared to the thymine-thymine carriers.

Thus, the human cannabinoid receptor 1 genotypes are closely related to two aspects of happiness. Compared to thymine-thymine carriers, the cytosine allele carriers of the human cannabinoid receptor 1 gene, who are sensitive to positive emotional stimuli, exhibited greater magnitude positive emotions when they experienced positive events and had a higher subjective happiness level.

Continue reading

Standard
Cannabis, Neuroscience

The Munchies, Marijuana and Happiness — Psychology Today

Link: The Munchies, Marijuana and Happiness | Psychology Today

When we are depressed our brains undergo many different biochemical changes; no one is quite certain which of these actually cause the typical feelings of sadness or hopelessness.

One important depression-related change is a dramatic decline in the birth of immature neurons, known as neurogenesis, in a brain region called the hippocampus.

Drugs that treat depression, such as Prozac and Zoloft, all induce a recovery in the rate of neurogenesis in the hippocampus.

So what’s the connection with marijuana and the munchies?

The drug, rimonabant, that was so successful in reducing food cravings as it induced depression and thoughts of suicide, has been recently shown (by Beyer and colleagues at Pfizer) to significantly reduce neurogenesis.

Let’s flip this idea on its side and ask, “What would happen to neurogenesis if we exposed the brain to marijuana?”

My lab investigated this idea and discovered that a small dose of marijuana, about only one puff, taken every day can reverse the age-related decline in neurogenesis that might underlie depression.

Whether this approach might also work in young people remains to be determined.

What these studies teach us is that our brain’s own marijuana neurotransmitter system is necessary for us to feel hungry, to experience happiness and to maintain the brain normal processes, such as neurogenesis, that prevent age-associated depression and cognitive decline.

We’ve learned from our experience with rimonabant that it is dangerous to constantly antagonize this neurotransmitter system.

What we do not know is whether it is dangerous to constantly stimulate it.

Standard