3. Umbruch 4.4..2005 - Online Pot

144 R.E. Musty
effects. Low doses seem to be anxiolytic, while high doses are anxiogenic. In
addition, it seems that the context is important. Further research is needed to
sort out the differences among various studies, but it is clear that both antagonists
and agonists on the CB 1 receptor have anxiolytic properties.
Standardization of behavioral testing procedures across laboratories would be
helpful, the problem being that there are many variables which have not been
explored with behavioral methods used to test for anxiolytic properties. Since
it is widely known that activation and inactivation of CB 1 receptors has a multitude
of modulator effects on neurotransmitter systems, it would be advantageous
for researchers to examine what changes in neurotransmitter activity
occur in conjunction with the pharmacological effects observed in the types of
studies cited herein.
Human studies
Consroe et al. [15] found that anxiety was reduced in 85% of patients with
multiple sclerosis in a self-report questionnaire. In another self-report study
[16] patients with spinal cord injuries reported similar reductions in anxiety.
In a laboratory setting, when subjects were instructed to smoke marijuana
until they reached their “usual” level of intoxication, regression analysis of a
visual analog scale of the word “anxious” predicted decreased scores on this
scale. These data support the hypothesis that THC has anxiolytic properties at
low doses [17].
In normal volunteers, Zuardi et al. [18] tested the hypothesis that CBD
would antagonize anxiety induced by THC. They used a dose of 0.5 mg/kg
THC for a 68-kg subject, which is a rather large dose, exceeding the dose a
person would take for the intoxicating effect of the drug. Subjects report a
pleasant high at 0.25 mg/kg using the same route of administration without an
increase in anxiety. In a second study Zuardi et al. [19] induced anxiety in normal
subjects by having them prepare a 4-min speech about a topic from a
course they had taken during the year. They were told the speech would be
videotaped for later analysis by a psychologist. The subject began the speech
while viewing his/her image on a video monitor. Anxiety measures were taken
using the Visual Analogue Mood Scale (VAMS), which yields measures on
four factors (anxiety, physical sedation, mental sedation and other feelings,
e.g. interest) at five time points: baseline, immediately before instructions,
immediately before the speech, in the middle of the speech and after the
speech. Heart rate and blood pressure measures were also taken. The subjects
were randomly assigned to one of four drug conditions: CBD (300 mg),
isapirone (5 mg), diazepam (10 mg) or placebo. CBD, diazepam and isapirone
decreased anxiety and systolic blood pressure. Neither CBD nor isapirone had
effects on physical sedation, mental sedation, or other feelings, but diazepam
induced feelings of physical sedation.