Why is whole plant marijuana not approved? Concerns focus on abuse liability, safety and effectiveness.
Abuse liability. Marijuana has high abuse potential, no currently approved medical use and is considered unsafe. At least 4.2 million Americans have a cannabis (marijuana) use disorder, with about 30.5 percent of current marijuana users harboring this problem. Long-time heavy users can experience a robust withdrawal, reflecting adaptive changes in the brain and body caused by the drug. Shortly after use, marijuana intoxicates and impairs higher brain functions, learning, memory, planning, and decision-making. Driving skills are reduced and the risk for injuries increases. Functioning at school or at work is compromised, especially because marijuana takes so long to clear from the body, days to weeks, and much longer compared with an alcohol binge. Complex human performance can be impaired as long as 24 hours after smoking a moderate dose of marijuana and the user may be unaware of the drug’s influence. For 7 to 20 days, abstinent marijuana users may have impaired attention, concentration and impulse control. The most robust, durable deficits are documented in heavy, steady marijuana users. Even after one month of withdrawal, daily, heavy marijuana smokers can manifest impaired higher brain functions. Yet the indications for marijuana are for chronic medical conditions, requiring daily or more frequent use.
Safety. There is a strong association between marijuana use and psychosis or schizophrenia, in at least four ways: (1) marijuana can produce transient schizophrenia-like symptoms in some healthy individuals; (2) in those harboring a psychotic disorder, marijuana may worsen the symptoms, trigger relapse, and negatively affect the course of the illness; (3) susceptible individuals in the general population develop a psychotic illness with heavy marijuana use, which is associated with age of onset of use, strength of THC in marijuana, frequency and duration of use; (4) marijuana use is associated with lowering the age of onset of schizophrenia. Among youth, marijuana use is associated with poor grades and with high school drop-out rates, with those dropping out of school engaging in high rates of frequent marijuana use. Early use of heavy marijuana is associated with lower income, lower college degree completion, greater need for economic assistance, and higher unemployment. In sum, marijuana use is associated with an increased risk of degraded brain function, increased motor vehicle crashes, emergency department visits, psychiatric symptoms, reduced educational and employment achievement, reduced motivation, increased use of, and addiction to other drugs, and adverse health effects on the developing fetus.
Effectiveness. The FDA is not the only body that has questioned the effectiveness of marijuana. Non-government academic physicians and scientists have extensively scrutinized biomedical research (meta-analyses) on the use of whole plant marijuana for medical indications. Independently, they have concluded that there is scant, inadequate or no evidence that whole plant medicine is valuable as a first line treatment for a myriad of medical conditions claimed by the marijuana lobby. For edibles, rigorous evidence is at zero or near-zero levels. Indeed, many specialty medical associations (Neurology, Psychiatry, Bertha K.
Bertha Madras is a professor at Harvard Medical School.