Study Finds Heavy Drinking, Drug Abuse Linked To Schizophrenia
According to a recent Danish study, persons who regularly engage in heavy drinking or take illicit drugs are much more likely to develop schizophrenia. Moreover, ANY abused substance increased risk. Previous studies have fingered cannabis as a risk factor for schizophrenia, and this study was no different. However, it’s not the only substance, by any means.
About The Study
Researchers found that the risk for schizophrenia was more than 5 times higher with cannabis use. It was 3.4 times higher with alcohol abuse, and nearly 2 times higher with use of hallucinogenic drugs. According to researchers, other substances, such as sedatives and amphetamines, also increased the risk.
The research team hailed from Copenhagen University Hospital. The study itself was based on information retrieved from over 3 million Danes. Of these persons, more than 204,000 had a history of substance abuse, and more than 21,000 had schizophrenia.
A word of caution, however – correlation does not imply causation. That is, researchers could not determine if alcohol and illicit drug abuse actually cause schizophrenia. It’s also possible that people who at at risk of schizophrenia development are also using substances as as form of self-medication, and therefore more likely to abuse them.
The findings have not been published in a peer-reviewed journal, but the preliminary results were presented as a poster at the International Early Psychosis Association (IEPA) meeting in Milan, Italy.
How Are Children Affected?
The same researchers also presented, in a press release, the results from yet another preliminary study. This one sought to determine if parental substance abuse could be associated with schizophrenia development in their children.
They found that the risk of a child developing schizophrenia when the mother had taken cannabis before giving birth increased 6 times over – and somewhat oddly, a similar risk was seen if used after birth. Researchers believe this may be the result of secondhand exposure.
When the father used cannabis, the risk increased by 5.5 times, regardless of when the drug was used.
In addition, maternal alcohol abuse, diagnosed before childbirth, was associated with a 5.6 increase in risk of the child developing schizophrenia. This number fell to just twice the risk for a diagnosis after birth, and the result for fathers engaged in heavy drinking was similar.
According to the authors:
“Second-hand exposure to cannabis is apparently linked to schizophrenia. While it is easy to be exposed to second hand smoke, with other substances, such as alcohol, there is no second hand exposure, which could explain the much lower associations observed after birth for these substances.”
~ G. Nathalee Serrels, M.A., Psychology