Transcript
Page 1: Cannabis and Schizophrenia - Grinspoon

—10 — O’Shaughnessy’s • Winter/Spring 2008

Cannabis and Schizophrenia

“There is now sufficient evidence towarn young people that using cannabiscould increase their risk of developing apsychotic illness later in life,” accord-ing to a paper in the Lancet July 28.

The “evidence” was produced by anexercise in statistics. The authors (noMDS among them) searched databasesfor relevant studies and then analyzed35 of them deemed worthy. They claimto have “adjusted for about 60 differentconfounding factors, including othersubstance use, personality traits, socio-demographic markers, intellectual abil-ity and other mental health problems.”They concluded that people who haveused cannabis face a 40% higher risk ofpsychosis, and that heavy use increasesthe risk to 50-200%.

Political ContextThe British government has been re-

considering the legal status of cannabis,which in 2004 was moved from Class Bto Class C —a less dangerous drug cat-egory with less onerous penalties forgrowers, distributors and users. Prohi-bitionist forces —notably the big drugcompanies and law enforcement— pro-tested. In 2005 the Advisory Council onthe Misuse of Drugs reviewed the medi-cal literature, held hearings and con-cluded that Class C indeed was the ap-propriate category. The Council’s reportstated “for individuals, the current evi-dence suggests, at worst, that using can-nabis increases the lifetime risk of de-veloping schizophrenia by 1%.” The lat-est Lancet paper is being played as atrump card to that report:

• “Weed May Make You Go Psycho” —Daily Mail

• “Smoking Just One Cannabis JointRaises Danger of Mental Illness by 40%”

—Daily Telegraph• “Cannabis Use Doubles Chance ofPsychosis” —The Independent on Sunday

The Independent on Sunday supple-mented its coverage of the Lancet paperwith a survey headed “50 Top ExpertsConfirm Mental Health Risk.” The IoShas led the campaign to return cannabisto Class B. Their poll does not and liter-ally could not “confirm” the risk posedby cannabis, it can only “confirm thatmost believe...” as the story explains: “Apoll of more than 50 of the world’s lead-ing authorities on drugs and mentalhealth, confirms that most believe can-nabis, and particularly its stronger vari-ant, skunk, pose significant health risksand increase users’ susceptibility to psy-chosis and schizophrenia.”

We sought a 51st opinion from LesterGrinspoon, MD, professor of psychia-try emeritus at Harvard who has beenstudying marijuana since 1967 and is theco-author of Schizophrenia: Pharmaco-therapy and Psychotherapy and othertextbooks. “It is hard to refute a studythat alleges certain things are going to

Schizophrenia is caused by damaged genes or an insult in the wombor infancy that results in malfunction when the brain develops andgets exposed to hormones produced in adulthood. What role, if any,does cannabis play in this process? We asked Lester Grinspoon, MD.

The Unambiguous Dangers of CannabisAccording to John Macleod (lead author of the Lancet’s 2004 meta-analy-

sis), “It is unfortunate that the debate around whether cannabis causes schizo-phrenia has become conflated with the debate around the legal status of can-nabis, and that this question has come to dominate discussions around the ap-propriate public-health response. The public-health case for prevention of can-nabis use by young people is strong, irrespective of whether use also causesschizophrenia.”

And what does Macleod see as “the public-health case” against young peopleusing cannabis? “Most users seem to smoke cannabis with tobacco,” he writes.“Cannabis use can actually lead to initiation of tobacco use, reinforce toxiceffects of tobacco, and make abstinence from tobacco more difficult. More-over, in most jurisdictions, cannabis use exposes young people to risks ofcriminalisation that could have additional consequences for their health.”

happen in the years ahead,” he says, “butsmoking marijuana does not causeschizophrenia.”

Grinspoon and the psychiatric estab-lishment agree that schizophrenia iscaused by damaged genes or an insult inthe womb or infancy that results, whenthe brain develops and gets exposed tohormones produced in adulthood, in anorganic malfunction. There ensues abreak with reality, sometimes accompa-nied by visual hallucinations or “voices.”Very often the break has an apparent“precipitating event,” says Grinspoon, “aserious automobile accident, loss of aloved one, an alcoholic binge a bad re-action to LSD or even, I imagine, tomarijuana. But it’s important to distin-guish between ‘precipitating event’ and‘cause.’”

Can those teenagers at risk for schizo-phrenia be warned that cannabis shouldbe avoided? Grinspoon responds, “Wehave no way of identifying a pre-schizo-phrenic individual.”

The Lancet paper is “a meta-analysisof studies that are themselves flawed,”says Grinspoon (who discredited someof them himself). “It greatly exaggeratesthe risk to the individual.”

According to Grinspoon, the can-nabis-causes-psychosis line is disproved

by the absence of “even a blip in the in-cidence of schizophrenia in the US aftermillions of people started smoking mari-juana in the 1960s.” The prevalence ofschizophrenia in adults is about 1%worldwide and seemingly independentof whether or not cannabis use is wide-spread in a given country.

A meta-analysis published in the Lan-cet in 2004 (Macleod, et al) stated, “Can-nabis use appears to have increased sub-stantially amongst young people over thepast 30 years, from around 10% report-ing ever use in 1959-70, to around 50%reporting ever use in 2001 in Britain andSweden. If the relation between use andschizophrenia were truly causal and ifthe relative risk was around five-fold,then the incidence of schizophreniashould have more than doubled since1970. However, population trends inschizophrenia incidence suggest that in-cidence has either been stable or slightlydecreased over the relevant time period.”

This sweeping, common-sense refu-tation of a causal link can only be gottenaround by defining currently availablecannabis as a new and different drug —which is what the prohibitionists aredoing with their “skunk” appellation.

But the increase in THC content isnot a sudden phenomenon, it has oc-curred over the course of decades (docu-mented in the U.S. by DEA analysis ofconfiscated cannabis). The incidence ofschizophrenia has not risen correspond-ingly. Nor has the widespread use ofMarinol —synthetic THC available inthe US since 1987— resulted in a higherincidence of schizophrenia.

Unmentioned in the media responseto the Lancet paper of July 28 is the factthat Prohibition has prevented growersfrom developing cannabis strains highin cannabidiol (CBD), a component ofthe plant that counters the anxiety- andconfusion-producing effect that THCexerts on some people.

Classification of Drugs in the UKClass A (most harmful) includes co-

caine, heroin, ecstasy and LSD.Class B (intermediate) includes am-

phetamines, barbiturates and codeine.Class C (least harmful) includes can-

nabis, benzodiazepines, anabolic ste-roids, and GHB.

juana website ( www.rxmarihuana.com)where you will find a published paperon this topic under the Publications Sec-tion, and in the section on Shared Expe-riences a number of accounts written bybipolar users who have found marijuanamore useful than conventional medi-cines.

Unfortunately, while you will not findmany physicians who are familiar withthe possibility that in some patients suf-fering from this disorder, it would ap-pear to be the “medicine of choice” be-cause for these people it works best andit is surely less toxic than conventionalmedicines. It is also, even with the pro-hibition tariff, often less expensive.While I cannot assure you that it will beuseful to your son (although he has someexperience which suggests that it is) itis unlikely to be harmful to him. It wouldbe best if he could find a psychiatrist whowould be willing to follow him as heexplores this possibility.

If after looking at the material men-tioned above you have questions, I willbe glad to try to answer them. Your sonsuffers from a very difficult disorder andI hope that you will find these sugges-tions helpful.

Sincerely yours,Lester Grinspoon, MD

Bipolar from previous page

A million kids in the U.S. are nowdiagnosed with “Bipolar Disorder,”which used to be known as “Manic De-pression” and occurred only in adults.On “Sixty Minutes” Sept. 30 KatieCouric did a jailhouse interview with themother of a four-year-old girl namedRebecca Riley who died from an over-dose of pharmaceutical drugs prescribedfor Bipolar Disorder. Rebecca’s parentsare charged with murder. Her mother hadtaken Rebecca at age two-and-a-half toa psychiatrist at Tufts-New EnglandMedical Center who labeled her bipolarand soon had her on a stew of Seroquel,an “unconventional antipsychotic,”Depakote, an anticonvulsant, andClonidine, a blood pressure drug. On thefatal night Rebecca had the sniffles; hermother gave her Children’s Tylenol PlusCough & Runny Nose and, when shecouldn’t sleep, half a Clonidine. She wasdead by 6 a.m.

Tufts-New England issued a state-ment: “The care we provided was appro-priate and within responsible profes-sional standards.” Couric quoted Dr.Kifuji’s lawyer to the same effect:“shewas just practicing mainstream psychia-try.” Couric then went to “one of the

Couric asked how a million kids cameto be labeled bipolar. Biederman said,“The idea is rare if you define it in verystrict ways. Our contribution has beento describe the many ways that this con-dition may emerge in children that maymake it a little bit more diagnosable andless rare than people have thought aboutit.”

Dr. Biederman’s contribution hasbeen to widen the customer base for thepharmaceutical manufacturers, which iswhy he’s so well-funded and highly po-sitioned within psychiatry. Couric, to hercredit, explained that the bipolar diag-nosis for adults used to involve extrememood swings that can last for months.“Dr. Biederman’s definition for children,though, is much broader. It emphasizesextreme irritability and at least four othersymptoms such as recklessness, sleep-lessness and hyperactivity.” Cut toBiederman behind his desk: “The aver-age age of onset is about four. It’s sol-idly in the preschool years.”

Tod Mikuriya. MD, was the antith-esis of Biederman —his polar opposite.

See “Cannabis as a first-line treat-ment for childhood mental disorders,”page 7.

One reason “bipolar” diagnoses are soaring

leading proponents of the diagnosis ofbipolar disorder in children, whose re-search Dr. Kifuji said had influenced her.He is Dr. Joseph Biederman, professorat Harvard and head of child psycho-pharmacology at Mass General Hospi-tal.”

Harvard’s Biederman has influencednot just Dr. Kifuji but the entire field ofchild psychiatry. He is the most citedauthor of “scientific” papers on ADD/ADHD (thanks to which 5 millionAmerican kids are on strong stimulants)and has done more than anyone to pro-mote “Bipolar” from a rare disorder to acommon one. Biederman has a sternmanner, and speaks in a German-sound-ing accent. His parents were Czech, hegrew up in Argentina.

Dr. Joseph Biederman of Harvard MedicalSchool has promoted “Bipolar” from arare disorder to a common one.

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