While marijuana popularity and acceptance is on the rise, so too are some not so pleasant statistics in states where use has been legalized — and opponents of marijuana legalization are pointing the finger directly at the drug as a mitigating factor.

For the Highway Loss Data Institute, the fact that car accidents rose significantly in a year’s time in four states where marijuana use was legalized and a comparison of similar states without marijuana legislation did not show a similar increase means marijuana made the difference.

Likewise, medical professionals are warning that marijuana use may be linked to psychosis, although the how and why and the valid source backup needed are all currently vague. Those proponents of marijuana remaining illegal maintain that more study is needed to back up or refute their proposed findings.

Meanwhile, doctors like Sue Sisley have spent time, and $2.1 million in grant money, to complete studies related to veterans and their use of marijuana to treat Post-Traumatic Stress Disorder. These medical professionals maintain that marijuana use is benign and the benefits far outweigh potential issues and the idea that psychosis and marijuana are strongly linked is laughable.

The Drug Policy Alliance, which advocates for marijuana legalization wherever possible, notes the evidence to back up these concerns is negligible. Arrests for driving under the influence of marijuana have not increased, and this, rather than crash statistics, is a better way to measure impact on the states who have opted to legalize.