Cannabis and the gene for happiness

A new study shows that a gene responsible for the effects of cannabis may explain why some people are naturally happier than others.

Scientists in Japan measured happiness levels among nearly 200 people and found that those who had a variant of the gene were happier on average and responded more positively to emotional stimuli. The gene identified encodes the CB1 receptor, the brain pathway responsible for cannabis psychoactivity.

 "The human cannabinoid receptor genotype 1 is closely linked to the two aspects of happiness," the researchers wrote. The study was published this month in the open-access journal PLOS ONE.

CB1 receptors are highly concentrated in the brain and act to alter appetite, pain, mood and memory.

According to the group, a polymorphism of the CB1 receptor gene can enhance an individual's response to cannabinoids, which are the chemicals that activate the pathways. More than 60 different cannabinoids have been identified in Cannabis, with Tetrahydrocannabinol (THC) usually having the highest concentration.

The study does not include cannabis smoking. As it turns out, the human body produces some cannabinoids on its own.

Like THC, these natural compounds act on various happiness-related areas of the brain and appear to act as mood regulators. In fact, one of the first cannabinoids discovered in man, the anandamide, got its name from the Sanskrit word Ananda, meaning bliss or pleasure.

Interestingly, when the researchers scanned the brains of individuals with the gene variant, they observed higher levels of activity in the regions that regulate positive emotions. By being more prone to the effects of cannabinoids, positive emotions can, in turn, explain why people with diversity are generally happier, the team says.

The researchers conclude that those with the CB1 gene variant are more likely to have a "high sensitivity to positive emotional events" and therefore "positive life events may be more abundant" for these individuals.