More and more studies have demonstrated that patients who use marijuana frequently or heavily have a higher risk of developing psychotic symptoms than nonusers. In those already predisposed to developing psychoses, evidence demonstrates an increased risk of early-onset psychotic symptoms in those who use marijuana.\cite{4}

Even over a decade ago, there was a reasonable body of evidence demonstrating that regular cannabis use predicts an increased risk of schizophrenia, which at the time led to the conclusion that use of cannabis can precipitate schizophrenia in those vulnerable to developing the disease (such as those with familial predisposition).\cite{5}

In response to the inevitable question of correlation—whether those patients with psychiatric mental illness are just more likely to use marijuana—evidence is emerging that marijuana may play a causal role in development of psychosis\cite{6}, more research must be done to confirm these results. In any case, it is important to note that across these studies demonstrating the relationship between marijuana use and psychiatric symptoms, the risk of psychiatric effect seems to increase with higher THC concentration.

Even beyond psychosis, the interactions between cannabis and the brain remain largely unknown. Preliminary studies show that THC binds to cannabinoid receptors in the nervous system, resulting in changes in mood and appetite, and perhaps long-term changes in verbal learning and memory; imaging studies have also demonstrated changes in structure and function of the brain with regular cannabis use.\cite{7}

\section{The Punchline? We Need Real Research}

\subsection{Roadblocks}

Since 1970, marijuana has been classified as a schedule I substance, a category the Drug Enforcement Agency (DEA) maintains for "drugs with no currently accepted medical use and a high potential for abuse." Marijuana shares this designation with drugs like heroin, LSD, and MDMA, among others. As one might imagine, this characterization has come under particular fire from proponents of medical marijuana use, who argue that the drug has demonstrated medical benefit for certain indications.

\begin{quote}
We should not legalize marijuana until we better understand what it really does to the brain.
\end{quote}

For the past 50 years, the only source of marijuana for federally funded research is one marijuana farm at the University of Mississippi, contracted through the National Institute on Drug Abuse. The limitations of this arrangement are many, including that the concentration of THC in the plants grown at this facility is not even close to representative of the concentration in recreational-use marijuana today. The scientific community seems unified in its expressed desire for more robust and thorough research. Francis Collins, director of the National Institutes of Health, has been particularly open in calling for fewer restrictions on research. In addition to his concerns about limitations in amount and quality of the plant available for research, he has also expressed the importance of studying the drug in its pure form, an effort that has been hampered by its DEA scheduling.\cite{8} According to Collins, "we know far too little about the benefits and risks of smoked marijuana" because "there have been very few studies that have actually rigorously tested that."

\subsection{Facilitating Real Research on the Drug}

One oft-discussed avenue for increasing research is reclassification of marijuana out of schedule I. In theory, this change could help lift logistical barriers and signal a shift in willingness to allow and support research. However, the DEA seems to be caught in a self-defeating cycle of justifying schedule I classification based on lack of scientific evidence of medical value, while hampering efforts to obtain this scientific evidence through schedule I classification.

Evidently, the DEA does not think reclassifying marijuana is the only way to facilitate research. In an