The effect of marijuana use on the risk for schizophrenia.

C or marijuana, is one of the most commonly used illicit drugs, but the debate rages in several countries regarding whether or not it should be legalized. With marijuana’s legalization come serious considerations for the medical community, such as What are the consequences of long-term use? What are the medical and psychological risks? and Who are the people most vulnerable to its negative effects? For example, are those with a predisposition for developing schizophrenia likely to have an earlier age at onset if they use marijuana? Recent research1 has revealed a connection between cannabis use and schizophrenia outcomes later in life, especially in adolescent cannabis users. Schizophrenia, which affects about 2.4 million Americans, is a chronic brain disorder that causes substantial disability2 and has a high worldwide cost and burden of care.3 Although no cure is available, tools can help clinicians accurately diagnose and treat the condition, and possible genetic markers may outline future treatment targets. Because the typical age at onset for schizophrenia is between 18 and 25 years, pediatricians as well as family practitioners and psychiatrists who see young patients should screen them for marijuana use and educate patients and parents on the associated risks. A. Eden Evins, MD, MPH, assembled an international group of experts to discuss the effect of marijuana on the risk for schizophrenia. The group addressed risk factors of schizophrenia, consequences of cannabis use, the potency of different types of cannabis and its effects, the effects of concurrent alcohol and tobacco use with cannabis, and the implications of legalizing marijuana.