As covered in previous posts, the 4th annual review of the impact of pot legalization on Colorado was recently issued by the Rocky Mountain High Intensity Drug Trafficking Area (RMHIDTA). In addition to the effect on youth use of THC products, the review also examines pot use by adults. The results are similar to the increases seen for youth and are summarized in part as:

Colorado Adult use of THC products


  • College age past month marijuana use increased 17 percent in the two-year average (2013/2014) since Colorado legalized recreational marijuana compared to the two-year average prior to legalization (2011/2012).
  • Nationally college age past month marijuana use increased 2 percent during the same timeframe.
  • The latest 2013/2014 results show Colorado college age adults ranked #1 in the nation for past month marijuana use, up from #3 in 2011/2012 and #8 in 2005/2006.
  • The latest 2013/2014 results show Colorado adults ranked #1 in the nation for past month marijuana use, up from #7 in 2011/2012 and #8 in 2005/2006.
  • The top ten states for the highest rate of current marijuana use for 2013-2014 were all medical-marijuana states

As mentioned in previous posts, an 8-point drop in IQ has been linked to THC use by youth, so are there problems associated with adult use of THC products?

Just one example from the RMHIDTA report summarizes a study done by Harvard scientists on the brains: “According to a study performed by researchers at Harvard and Northwestern (published 4/15/2014), 18-25 year olds who smoked marijuana only a few times a week had significant brain abnormalities in the areas that control emotion and motivation. Noticeable abnormalities were even observed for those study participants who smoked marijuana only one time per week. Those who smoked more had more significant variations.”

Missing from the RMHIDTA report, but a key ramification of the increased use of THC products are the costs of use and addiction that will fall to taxpayers and communities. In many cases these costs will be buried in other statistics such as the rising cost of medical treatment, the impact of driving under the influence of THC or the long term impacts that accrue due to brain abnormalities.

Unfortunately, the impact of increased THC use tends to impact the poorest amongst us as covered in this summary taken from the report:

A study published “…in the Journal of Drug Issues found that the proportion of marijuana users who smoke daily has rapidly grown, and that many of those frequent users are poor and lack a high school diploma.” According to the study the profile of marijuana users is much closer associated to that of cigarette smokers than alcohol drinkers, “…and that a handful of users consume much of the marijuana used in the U.S.” Also, 29 percent of all marijuana use across the county is from households with an annual income of less than $20,000. “The concentration of use among poorer households means that many marijuana users are spending a high proportion of their income on their marijuana habit. Users who spend fully one quarter of their income on weed account for 15 percent of all marijuana use.”