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Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study

BMJ 2011; 342 doi: (Published 01 March 2011) Cite this as: BMJ 2011;342:d738

Cannabis Indica vs Sativa

The article failed to specify whether the patients in the study were
using Cannabis indica, Cannabis sativa, or an indica/sativa hybrid.

Cannabis does not refer to one plant, but several, just as Canine refers
to several animals: dogs,wolves,foxes,& coyotes. The two main types of
cannabis are indica and sativa, which are as different as dogs and wolves.

Sativas have high relatively unopposed THC (hallucinogen) levels. This
tends to be activating, but in some people it can cause increased anxiety
and even paranoia. Long term use can result in effects similar to those of
long term high dose amphtamine use. Indicas have relatively higher
canabadiol (CBD) levels which moderate the effects of the THC that is
present. Indicas tend to be so sedating that most people can only use
indicas at night. I like to use the analogy of sativas being like wolves
and indicas being like dogs with as many strains as there are breeds of
dogs. Just as there are dog/wolf hybrids, there are also sativa/indica
cannabis hybrids. These are usually used duing the day to avoid the excess
sedation of the indica and the excess agitation of sativa. I have noted
that patients with bipolar disorder who use pure cannabis sativa tend to
develop psychosis. Bipolar patients who use only cannabis indica at night
or an indica at night and a hybrid (preferably indica dominate) during the
day, with no pure sativa, seem to stay stable.

I would like to see future studies which differentiate the use of C.
indica from C. Sativa.

Competing interests: As a part of my General Medical practice I also do addiction medicine and medical cannabis evaluations.

28 March 2011
Aury L. Holtzman,M.D.
Beach Medical Center