As decriminalization of marijuana is rapidly spreading across the United States, more researches are being conducted to highlight the health risks associated with smoking pot.
A new research shows that marijuana can considerably augment the risk of depression and anxiety.
Twenty-three states in the U.S. and the District of Columbia have passed laws permitting some degree of medical use of marijuana and 14 states are planning to decriminalize the use of pot to an extent.
According to the latest research, smoking marijuana aggravates the risk of anxiety and depression. The brains of the pot users have reduced response to dopamine, the neurotransmitter that activates motivation for seeking reward.
The study was conducted on a small number of subjects. Researchers divided them into groups of two - marijuana users and controls (each containing 24 participants). Researchers then performed personality tests and brain scans of the respondents.
The study results showed that pot smokers had significantly lower dopamine responses compared to the control group.
Lower levels of dopamine might be one of the reasons for drug craving, depression and anxiety, researchers explained.
"Marijuana abusers show lower positive and higher negative emotionality scores than controls, which is consistent, on one hand, with lower reward sensitivity and motivation and, on the other hand, with increased stress reactivity and irritability," researchers wrote in the study.
"We found that marijuana abusers display attenuated dopamine (DA) responses to MP, including reduced decreases in striatal distribution volumes. These deficits cannot be unambiguously ascribed to reduced DA release (because decreases in nondisplaceable binding potential were not blunted) but could reflect a downstream postsynaptic effect that in the ventral striatum (brain reward region) might contribute to marijuana's negative emotionality and addictive behaviors," they added.
"Moves to legalize marijuana highlight the urgency to investigate effects of chronic marijuana in the human brain," researchers concluded.
The study was published in the journal Proceedings of the National Academy of Sciences of the United States of America.
