(My comments are in red text)
This study, revealing the connection, is no surprise to those who look at pot use objectively, that cannabis has this correlation between using pot and schizophrenia, but it’s very unlikely that this study will show up in the media.
We, who read this type of information daily, know; we have known for decades.
As a former user, long before I was willing to admit it to myself, I watched others (friends who used), and knew that the immediate paranoia some began experiencing as soon as they got high, was not a good sign.
But it’s the legalizers and the media who present the lies to the public claiming pot is not only safe, but also medicinal ……
Also, as with some of my friends back then, I watched as their entire personalities and character traits radically changed, and some quickly – right before my eyes, yet it still took me way too long before the realization of all this, made me aware that other psychological and possibly even physiological / chemical changes were going on in the brain …… and that couldn’t be good!
What changed me? Why I quit using? I saw what it had done to my older children, but that long and painful story is for another time …… I’d remarried and we were pregnant. That was 32 years ago and I joined Drug Watch International; most of the members are people who are committed to trying to stem the tide of drug use because they’ve lost children to drugs!
The members of Drug Watch? They’re interested in seeing you don’t go through the same loss! And the legalizers? What’s their goal? To be able to get high without going to jail. Which is more altruistic?
A large, longitudinal cohort study shows that:
schizophrenia patients with a history of cannabis use had longer hospital stays, a higher rate of hospital readmission, and a type of schizophrenia “that may be more severe than schizophrenia cases in general,” according to study investigator Peter Allebeck, MD, PhD, professor of social medicine in the Department of Public Health Sciences at the Karolinska Institute in Stockholm, Sweden.
The findings were reported here at EPA 2013: 21st European Congress of Psychiatry.
Greater Severity, Poorer Prognosis
The researchers note that although there is increasing evidence of a link between cannabis use and schizophrenia, it is unclear whether the prognosis and outcomes in these patients differ from their non-cannabis-using counterparts.
To determine whether there are differences between these 2 patient populations, the investigators performed a longitudinal study of 50,087 male Swedish army conscripts aged 18 to 19 years between 1969 and 1970.
Participants underwent medical assessments as well as structured interviews by psychologists, including questions on family and socioeconomic background, work, leisure activities, and use of alcohol, drugs, and tobacco.
At baseline, there were no statistically significant differences between cannabis users and nonusers in terms of various psychiatric diagnoses. Follow-up through 2007 identified schizophrenia diagnoses, number of hospital admissions, and total durations of hospital stays, using an inpatient register.
Of the 50,087 patients, 5391 used cannabis. During follow-up, a total of 350 patients were identified as having schizophrenia, and of these, 58 used cannabis.
At first admission for schizophrenia, the only schizophrenia subtype showing a difference was paranoid schizophrenia (n = 56), for which cannabis users had a lower rate compared with nonusers (n = 6 [8%] vs n = 50 [17%]; P = .02).
The median duration of first hospital admission was almost twice as long for users as for nonusers (59 days vs 30 days). One third of users (34%) required more than 90 days, whereas only 20% of nonusers were hospitalized that long on first admission.
Similarly, cannabis users had a median of 10 readmissions vs 4 readmissions for nonusers. Nearly a third of the cannabis users had more than 20 readmissions — 29% of users vs 10% of nonusers.
“Those who had schizophrenia after cannabis use had many more hospital days…more than a third [38%] of those who had cannabis use had more than 2 years in total in hospital stay” compared with 21% of nonusers, said Dr. Allebeck. The median number of hospital days was 547 for cannabis users and 184 for nonusers.
After controlling for socioeconomic factors, personality disorders, IQ, and other factors associated with cannabis use, “there was more than 3-fold increased risk of such long hospital days among cannabis users,” Dr. Allebeck said (more than 730 hospital days for users vs nonusers; odds ratio, 3.4; 95% confidence interval, 1.3 – 7.3).
“The number of readmissions is also about 3-fold increased of those with many readmissions after the first admission for schizophrenia,” he said.
“Schizophrenia caused by or contributed by cannabis may be more severe than schizophrenia in general,” he concluded. “Patients with cannabis history seem to have more severe and more persistent history of schizophrenia, as indicated by duration of first admission, total duration of hospital days, number of readmissions. And these of course are true measures of severity and prognosis.”
Session chair Pierre Michel Llorca, MD, PhD, professor and chairman of psychiatry at the University of Auverge in Clermont-Ferrand, France, who was not involved with the study, commented to Medscape Medical News that although the study showed a higher risk for more severe schizophrenia among cannabis users, he remained a bit sceptical.
“For example, in France, you have an increase in the consumption of cannabis, which is incredible during the last 20 years,” he noted and said that if cannabis use were directly related to schizophrenia, there should be an increase in its incidence. “And it’s not the case.”
The study cohort at baseline consisted of young army conscripts, but that does not really define it. He said he would like to have seen more precision about the study population “and the comparison that we can have with the whole population.”
Dr. Llorca also questioned how the researchers defined the actual doses of tetrahydrocannabinol received, because it is very hard to tell just on the basis of the amount of cannabis consumed, owing to the varying strengths and how it was delivered (eg, depth and length of inhalation).
Other unevaluated variables were the heterogeneity of the cohort, the subtypes of schizophrenia, and the possible consumption of other drugs or supplements. Still, he praised the study for its length of follow-up and added that methodological issues in such longitudinal studies are not unusual.
Dr. Allebeck reports no relevant financial relationships. Dr. Llorca is a speaker for Otsuka, Janssen, and Roche, and he has received research support from Lundbeck.
EPA 2013: 21st European Congress of Psychiatry Conference. Abstract 1697. Presented April 7, 2013