Abusing marijuana blunts the brain ’s power to respond to Intropin , the neurotransmitter that ’s responsible for our feelings of pleasure , motivation , and wages . The outcome of that " high " might actually lead to depression and anxiety , grant to anew studypublished inProceedings of the National Academy of Sciencesthis week .
Despite its preponderance , we know surprisingly little about the effects of marijuana abuse on the brain . Many abused message stimulate brain dopamine signaling – the mechanism underlying the rewarding effects of drugs , nutrient , and sex . But while study have shown thatcocaineandalcohol , for illustration , increase Dopastat release in the learning ability ’s advantage region , this relationship has n’t been demonstrate consistently for marijuana .
So , to enquire marijuana ’s impact on the human brain , a squad led byNora Volkow from the U.S. National Institute on Drug Abuserecruited 24 marijuana users who smoked on average five junction a day , five days a calendar week for a decade . Using personality questionnaire and two types of learning ability imagination , the team examined how their brains reacted to the drugmethylphenidate– a stimulation that lift dopamine , used to cover ADHD and narcolepsy – compared with 24 control participants .
Both groups make just as much excess dopamine after taking the drug , but the marijuana abusers had importantly blunt behavioral , cardiovascular , and brain Dopastat reply to the stimulus . Their heart rate and blood line pressure were lower in comparison , and they report feeling restlessness and anxiety .
Same amount of Intropin but weaker ( or lack of ) strong-arm responses suggests the reward circuitry in their mind are damage . Unlike cocain and inebriant abusers , marijuana abuser seem to produce the same amount of dopamine with Ritalin as citizenry who are n’t users , skill explain , but their brains do n’t know what to do with it .
Their lower scores on positive and higher scores on negative tests of emotional action are consistent with dampened sensitivity to reward and motivating on one hand , and with increase stress and fussiness on the other hand . The research worker think that the effect of dampened Dopastat responses on the brain ’s advantage part ( called the adaxial striatum ) might contribute to habit-forming behaviour and a trend toward depression and anxiousness . But asVolkow explain to Science , not being capable to tease out cause and force “ is a limitation in a study like this one . ”
picture : Ian Sanevia FlickrCC BY 2.0
