This study was done on 109 women and 73 men, both being primarily Caucasian.

They wanted to see if there was a correlation between drinking behavior and anxiety sensitivity (AS).

The definition for AS is having anxiety over things like bad consequences, illness, mental incapacitation, or social embarrassment (McNally, 1996, Steward et al., 1997).

Their study shows that there is an association between frequent drinking behavior and AS levels.

My main concern with this study is that it is a prime example of causation versus correlation.

More studies would have to be done to determine whether alcohol causes increased AS levels or whether people with increased AS levels tend to gravitate towards alcohol.

I think a possible study to get to the bottom of this truth would be to survey the people and see if they experienced symptoms of AS before they began drinking heavily or after.

Of course, like most things in nature, the truth might be that it is a little bit of both.

15 individuals (12 women) with GAD--generalized anxiety disorder--participated in a venlafaxine treatment trial. 

GAD: A chronic disorder that can be described as excessive, pervasive, and uncontrollable anxiety that has been present for over six months.

Their brain was scanned with an fMRI as they made facial expressions (before the venlafaxine treatment).

Their brain was then scanned again, with the same expressions, after receiving the venlafaxine treatment.

There was also a control group which consisted of 15 individuals (also 12 women) who did not have GAD or the venlafaxine treatment.

The venlafaxine treatment lasted 8 weeks and all subjects were right handed.

The scans targeted the amygdala because it is in control of facial expressions and anxiety/fear.

Studying facial expressions has been proven to be a good way to observe anxiety, by extension of this the amygdala is the target part of the brain.

The subjects were proven to have GAD thanks to the SCID interview and physician interview. Also they took the HAM-A scale (Hamilton Anxiety Ranking Scale).

The data collected in this study shows that the treatment was successful in these individuals.

The study seems pretty sound, although there was no group who had GAD and received a placebo treatment.

21 Individuals in total--of them 14 right-handed males with no family history of psychiatric illness.

Whether or not the subject abused substances was noted.

For this experiment, the working definition of substance abuse was the moderate use of small quantities of the substance or the occasional usage of large amounts.

Subjects were told to refrain from drug use for 3 months prior to the study and during the study.

There were two tests done on the participants with the gap of one month between the tests.

In these tests, the drug administration was randomized--including a placebo drug.

Before studies, all subjects had a uniform schedule which regulated their sleep, consumption of food and drink, and drug usage.

The study shows that individuals under the influence of delta-9-THC report higher levels of anxiety than those who were in the placebo group.

fMRI scans show that the amygdala has an increased response to the viewing of fearful faces, increased anxiety, in individuals who were under the influence of delta-9-THC in comparison to the placebo group.

This study shows that delta-9-THC might actually increase the anxiety levels in individuals who do not have some form of anxiety disorder or other psychiatric illnesses.

Male and female Sprague Dawley (n=  264) and male Wistar (n=3) rats were used for this experiment.

They had access to water and food, unless noted otherwise.

Six separate cohorts were assessed for anxiety-like behavior.

In comparison to an overnight fast, eating every hour increased the rats' stomach contents.

Rats were injected CNO that activates vagal afferents terminating in the stomach and duodenum.

This study is important because it includes both male and female rats.

An important relationship was found between fasting and anxiety in these rats as a result of vagal afferents on behavior.

Cannabinoids (CBs) are associated with neuroprotective effects in vivo.

These effects were measured using lesioned organotypic hippocampal slice cultures (OHSCs).

8-day-old Wistar rats were decapitated and had their brains dissected under sterile conditions. The brains were placed in minimal essential medium.

OHSCs had a positive effect on neuronal preservation with unlesioned cultures.

In OHSCs lesioned with NMDA, a large accumulation of IB4+ microglial cells occurred at the site of neuronal injury. 

Treatment in lesioned slices with THC resulted in a large reduction of IB4+ microglial cells, this is true for AEA and 2-AG as well.

This is true for pre-treatment.

THC caused a concentration-dependent reduction in the number of microglial cells that were antagonized by the specific CB2R antagonist AM630 at 10 microM.

Thus, THC-induced redution of microglial cell number involces CB2R.

The relationship between adolescent cannabis use and long-term cognitive/affective dysfunction is assessed here.

Previous studies show that exposure to THC adversely affects long-term cognitive abilities. 

Long-Evans rats were used in this experiment.

They were houses in single sex groups of three and their cage was exposed to smoke for a certain period.

Smoke was used for this experiment rather than injections since humans typically inhale THC rather than inject it.

It is important to note that several rats began to fight with their cagemates shortly after the smoke sessions.

For the remainder of the experiment, the rats were single housed.

There was a normal 12 hour day/night cycle and the study consisted of 36 males and female rats.

THC, cannabis cigarettes, and placebo cigarettes were used. The placebo cigarette contained cannibis plant material which had the cannabinoids extracted.

Rats were exposed to smoke from cannabis or placebo cigarette burning.

There was a large open field test and elevated plus maze test to assess the anxiety-like behavior of the rats.

There was also a sucrose preference test--a reduced preference for the sucrose solution over water is a sign of anhedonia (lack of pleasure in life).

There was a forced swim test. The rats were considered immobile if they were floating in the water and only made the minimal effort to keep their head above the water.

The novel object recognition test was also performed. Exploring an object was defined as a rat pointing its head toward the object in which its nose was within 1cm of the object.

There was no significant effect of THC on the large open field test, elevated plus maze test, sucrose preference, forced swim test, and novel object recognition test.

This dosage of THC by smoke had no significant effects.