DEPRESSED? TAKE TWO AND PASS

Considering the lyrics of the many marijuana-inspired songs of the
past, like Bob Marley's entreaty not to "worry about a thing," one
may not be surprised to learn that recent research posits marijuana
as an effective anti-depressant. More surprising, perhaps, are the
findings that charge marijuana as the root of depression as well.

The latest research from the laboratory of Dr. Gabriella Gobbi, of
the Neurobiological Psychiatry Unit at McGill, implicates marijuana
use in inducing both depression and mood improvement. Individuals
receiving treatment for marijuana dependence are more likely to have
depression, while those seeking treatment for depression also show an
increase in marijuana use. These are interesting correlations, but
any causal relationship is unclear. Which came first, the depression
or the weed? Does marijuana use cause depression, or are depressed
individuals more likely to use marijuana?

Some see marijuana as a medication for depression. It seems intuitive
- - marijuana improves mood, if only temporarily, by inciting mild
feelings of euphoria in the user. Pot offers a happy alternative to
pharmacological anti-depressants, since marijuana can be quickly
obtained and is less physically addictive than most anti-depressants.

Gobbi's research supports this view: rats given a low dose of a THC
analogue (the active ingredient in marijuana) show a decrease in many
depression-related behaviours. Even more significantly, these effects
seem to be mediated via interactions with the serotonin pathway,
through which Prozac and most antidepressants act on the brain. Thus
there may be a neurological basis for marijuana's antidepressant effects.

At higher doses, however, marijuana use may actually cause
depression: acording to Gobbi, high doses of the THC analogue
decrease serotonin activity in the brain.

These findings shed light on new research avenues into the use of
cannabis in mood regulation, but much work remains to be done. "We
need more controlled human studies to determine the effects of
increased doses of THC in humans," Gobbi says. She adds that finding
a link between marijuana and depression is complicated, because
studies of human responses would need to take into account the
unpredictable strength of street marijuana. Furthermore, the many
active agents found in marijuana may have medical interactions with THC.

It seems that although marijuana use may provide relief to depression
in the short term, an inappropriate dose of marijuana may be
analogous to treating a stubbed toe with an amputation.