Boston, MA–(ENEWSPF)–December 20, 2013. Family genetics, rather than adolescent cannabis use, increases risk of schizophrenia, according to a case control study published online in the journal Schizophrenia Research.
Investigators from Harvard Medical School compared the family histories of 108 schizophrenia patients and 171 individuals without schizophrenia to assess whether youth cannabis consumption was an independent factor in developing the disorder. Researchers reported that a family history of schizophrenia increased the risk of developing the disease, regardless of whether or not subjects consumed cannabis as adolescents.
“There was an increased morbid risk for schizophrenia in relatives of the cannabis using and non-using patient samples compared with their respective non-psychotic control samples,” authors reported. “There was no significant difference in morbid risk for schizophrenia between relatives of the patients who use or do not use cannabis.”
They concluded: “The results of the current study, both when analyzed using morbid risk and family frequency calculations, suggest that having an increased familial risk for schizophrenia is the underlying basis for schizophrenia in these samples and not the cannabis use. While cannabis may have an effect on the age of onset of schizophrenia it is unlikely to be the cause of illness.”
Previous studies have reported that rates of schizophrenia have remained steady for decades despite changing patterns in cannabis use among the population.
Commenting on the study’s findings, NORML Deputy Director Paul Armentano said: “Concerns regarding cannabis’ potential impact on psychiatric illnesses arguably warrant further study. However, such concerns – even if confirmed – are not persuasive justifications for continuing cannabis criminalization. Just the opposite is true. There are numerous adverse health consequences associated with alcohol, tobacco and prescription drugs, all of which are far more dangerous and costlier to society than cannabis. It is precisely because of these consequences that these products are legally regulated and their consumption is restricted to specified consumers and settings. This same principle ought to apply to cannabis.”
Full text of the study, “A controlled family study of cannabis users with and without psychosis,” appears in Neuropsychopharmacology.
Source: http://norml.org
