The science is clear: Marijuana is a major public health risk

Discussions about the impact of legal marijuana on crime rates inevitably lead to substantial debate, although the data from the legalization experiments in Colorado and Washington State give compelling support to opponents of legalization.  There is significant evidence that crime has increased in these two jurisdictions following pot legalization.

The other side of the issue involves the health impacts of marijuana consumption.  And here there is far less room for rational disagreement.  A large number of scientific studies collectively show the adverse health effects of marijuana.

Indeed, the breadth and depth of these studies is far too large for a single comprehensive review that would be readable for a mainstream audience.  Thus, what follows is just a subset of the major findings reported by the scientific community in 2015 alone.  This list is far from complete, even though only 11 months of publication time in traditional science journals and books is being considered.

  • From a study in the The American Journal on Addictions: "Approximately 1 in 12 undergraduates (8.5 percent) reported using marijuana more than 10 days in the past month ... frequent use is related to depression, other substance use and negative outcomes."
  • From a study in the Journal of Drug Education: "[C]oncordant [both partners use] marijuana-using couples ... were at elevated risk for male-to-female partner violence[.] ... Husband-only marijuana discrepant [one partner uses] couples were at increased risk for female-to-male partner violence."
  • From a study in the Journal of Drug Issues: "Results showed marijuana users were more likely to use a variety of substances and engage in hazardous drinking than non-users."
  • From a study in the American Journal of Epidemiology: "Regular marijuana smoking more than once per week was associated with a 28 percent lower sperm concentration and a 29 percent lower total sperm count after adjustment for confounders[.] ... Marijuana smokers had higher levels of testosterone within the same range as cigarette smokers."
  • From a study in the American Journal of Preventive Medicine: "In the context of abrupt changes in marijuana policy in 2009 in Colorado, the authors sought to investigate corresponding changes in marijuana-related public health indicators[.] ... Hospital discharges coded as marijuana-dependent increased 1 percent per month from 2007 to 2013. A change in trend was detected in poison center calls mentioning marijuana. After 2009, poison center calls increased 0.8 percent per month. Poison center calls also increased 56 percent in the period following the policy change."
  • From a study in JAMA [Journal of the American Medical Association] Psychiatry: "The prevalence of marijuana use [in the United States] more than doubled between 2001-2002 and 2012-2013, and there was a large increase in marijuana use disorders during that time[.] ... [N]early 3 of 10 marijuana users manifested a marijuana use disorder in 2012-2013."
  • From a review article in Social Psychiatry and Psychiatric Epidemiology: "[I]ndividuals who use cannabis regularly, or who begin using cannabis at earlier ages, are at increased risk of a range of adverse outcomes, including: lower levels of educational attainment; welfare dependence and unemployment; using other, more dangerous illicit drugs; and psychotic symptomatology."
  • From a study in Health Education and Behavior: "[S]tudents who reported frequent recent alcohol or recent marijuana use were at increased odds of experiencing physical or verbal [teen dating violence] victimization compared to students who reported little or no alcohol or marijuana use."
  • From a review and perspective article in Clinical Pharmacology and Therapeutics: "There is certainly cause for concern about the amount and frequency of cannabis use among youth[.] ... Recent evidence shows that early and frequent use of cannabis has been linked with deficits in short-term cognitive functioning, reduced IQ, impaired school performance, and increased risk of leaving school early – all of which can have significant consequences on a young person's life trajectory ... Heavy cannabis use in adolescence is also a risk factor for psychosis ... Recent data from the National Fatality Database indicate that cannabis was the most common illicit drug present among fatally injured drivers aged 15-24 in Canada between 2000 and 2010 ... [Y]outh aged 15-24 spent the largest number of days in a hospital for a primary diagnosis of mental and behavioral disorders due to the use of cannabinoids."
  • From a review article in Current Opinion in Psychology: "Marijuana users are more likely to perpetrate intimate partner aggression than non-users."
  • From a chapter in the book on Cannabinoid Modulation of Emotion, Memory, and Motivation: "[A] chronically high level of [marijuana] consumption for an extended period of time is likely to result in increased risk of developing impairments such as affective dysregulation, inefficient cognitive control, underachievement, lower estimated intellectual capacity, and increased potential for additional drug use."

This list could go on and on.  Keep in mind that these are conclusions taken from a selection of studies published only in 2015.  If we included all studies over time, the evidence for the serious negative health impacts of marijuana becomes overwhelming.

Yet we haven't been reading about findings of this type each week in the mainstream media.  The reasons for this are easy to understand.

Depending on the source, estimates for the total value of the U.S. domestic marijuana market range up to $100 billion.  Big Pot is a big corporate endeavor, and such financial vested interests have a way of shaping media coverage in their favor through their direct and indirect control of editorial boards and senior management.

Legalized marijuana is also a trendy cause for many on the political left and in libertarian ranks, and the media also follows this herd all too often without critical examination.

As well, there are upwards of two million or more scientific studies published each year.  It is impossible for the media to stay on top of what is going on in science, and just as difficult – what with all the press releases the various research teams are putting out – to decipher which findings are truly important enough to spend time and money reporting on them, especially when page views rule the roost for the corporate outlets.

But the information is out there for interested members of the public to find, particularly concerned parents and educators.  Some dedicated efforts at browsing Google Scholar can inform those troubled about the long-term impacts of marijuana legalization regarding the real scientific facts, rather than the Big Pot propaganda.  And the facts point clearly to legalized marijuana being one of the most serious public health risks society is facing in the coming decades.

Discussions about the impact of legal marijuana on crime rates inevitably lead to substantial debate, although the data from the legalization experiments in Colorado and Washington State give compelling support to opponents of legalization.  There is significant evidence that crime has increased in these two jurisdictions following pot legalization.

The other side of the issue involves the health impacts of marijuana consumption.  And here there is far less room for rational disagreement.  A large number of scientific studies collectively show the adverse health effects of marijuana.

Indeed, the breadth and depth of these studies is far too large for a single comprehensive review that would be readable for a mainstream audience.  Thus, what follows is just a subset of the major findings reported by the scientific community in 2015 alone.  This list is far from complete, even though only 11 months of publication time in traditional science journals and books is being considered.

  • From a study in the The American Journal on Addictions: "Approximately 1 in 12 undergraduates (8.5 percent) reported using marijuana more than 10 days in the past month ... frequent use is related to depression, other substance use and negative outcomes."
  • From a study in the Journal of Drug Education: "[C]oncordant [both partners use] marijuana-using couples ... were at elevated risk for male-to-female partner violence[.] ... Husband-only marijuana discrepant [one partner uses] couples were at increased risk for female-to-male partner violence."
  • From a study in the Journal of Drug Issues: "Results showed marijuana users were more likely to use a variety of substances and engage in hazardous drinking than non-users."
  • From a study in the American Journal of Epidemiology: "Regular marijuana smoking more than once per week was associated with a 28 percent lower sperm concentration and a 29 percent lower total sperm count after adjustment for confounders[.] ... Marijuana smokers had higher levels of testosterone within the same range as cigarette smokers."
  • From a study in the American Journal of Preventive Medicine: "In the context of abrupt changes in marijuana policy in 2009 in Colorado, the authors sought to investigate corresponding changes in marijuana-related public health indicators[.] ... Hospital discharges coded as marijuana-dependent increased 1 percent per month from 2007 to 2013. A change in trend was detected in poison center calls mentioning marijuana. After 2009, poison center calls increased 0.8 percent per month. Poison center calls also increased 56 percent in the period following the policy change."
  • From a study in JAMA [Journal of the American Medical Association] Psychiatry: "The prevalence of marijuana use [in the United States] more than doubled between 2001-2002 and 2012-2013, and there was a large increase in marijuana use disorders during that time[.] ... [N]early 3 of 10 marijuana users manifested a marijuana use disorder in 2012-2013."
  • From a review article in Social Psychiatry and Psychiatric Epidemiology: "[I]ndividuals who use cannabis regularly, or who begin using cannabis at earlier ages, are at increased risk of a range of adverse outcomes, including: lower levels of educational attainment; welfare dependence and unemployment; using other, more dangerous illicit drugs; and psychotic symptomatology."
  • From a study in Health Education and Behavior: "[S]tudents who reported frequent recent alcohol or recent marijuana use were at increased odds of experiencing physical or verbal [teen dating violence] victimization compared to students who reported little or no alcohol or marijuana use."
  • From a review and perspective article in Clinical Pharmacology and Therapeutics: "There is certainly cause for concern about the amount and frequency of cannabis use among youth[.] ... Recent evidence shows that early and frequent use of cannabis has been linked with deficits in short-term cognitive functioning, reduced IQ, impaired school performance, and increased risk of leaving school early – all of which can have significant consequences on a young person's life trajectory ... Heavy cannabis use in adolescence is also a risk factor for psychosis ... Recent data from the National Fatality Database indicate that cannabis was the most common illicit drug present among fatally injured drivers aged 15-24 in Canada between 2000 and 2010 ... [Y]outh aged 15-24 spent the largest number of days in a hospital for a primary diagnosis of mental and behavioral disorders due to the use of cannabinoids."
  • From a review article in Current Opinion in Psychology: "Marijuana users are more likely to perpetrate intimate partner aggression than non-users."
  • From a chapter in the book on Cannabinoid Modulation of Emotion, Memory, and Motivation: "[A] chronically high level of [marijuana] consumption for an extended period of time is likely to result in increased risk of developing impairments such as affective dysregulation, inefficient cognitive control, underachievement, lower estimated intellectual capacity, and increased potential for additional drug use."

This list could go on and on.  Keep in mind that these are conclusions taken from a selection of studies published only in 2015.  If we included all studies over time, the evidence for the serious negative health impacts of marijuana becomes overwhelming.

Yet we haven't been reading about findings of this type each week in the mainstream media.  The reasons for this are easy to understand.

Depending on the source, estimates for the total value of the U.S. domestic marijuana market range up to $100 billion.  Big Pot is a big corporate endeavor, and such financial vested interests have a way of shaping media coverage in their favor through their direct and indirect control of editorial boards and senior management.

Legalized marijuana is also a trendy cause for many on the political left and in libertarian ranks, and the media also follows this herd all too often without critical examination.

As well, there are upwards of two million or more scientific studies published each year.  It is impossible for the media to stay on top of what is going on in science, and just as difficult – what with all the press releases the various research teams are putting out – to decipher which findings are truly important enough to spend time and money reporting on them, especially when page views rule the roost for the corporate outlets.

But the information is out there for interested members of the public to find, particularly concerned parents and educators.  Some dedicated efforts at browsing Google Scholar can inform those troubled about the long-term impacts of marijuana legalization regarding the real scientific facts, rather than the Big Pot propaganda.  And the facts point clearly to legalized marijuana being one of the most serious public health risks society is facing in the coming decades.