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It's true: Marijuana causes paranoia

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A new in-depth study published today in the journal Schizophrenia Bulletin, suggests that marijuana can cause certain psychological effects, which may result in paranoid thinking.

Previous studies have demonstrated that marijuana’s primary ingredient, delta-9-tetrahydrocannabinol (THC), alters the perceptions of marijuana users, inducing paranoid thoughts and other negative effects, such as hallucinations and delusions.

Study leader Prof. Daniel Freeman of the University of Oxford described cannabis-induced paranoia as excessively thinking that others are going to harm them, adding that whether or not to trust people is a common thought process in our life on a day-to-day basis.

However, he said that when our suspicions are wrong, it’s paranoia.

“Many people have a few paranoid thoughts, but few people have many paranoid thoughts,” Prof. Freeman explained.

There were 121 participants, ages 21 to 50, involved in the study. All of them were mentally health and had used marijuana at least once before.

In order to find out how THC affected the participants, and if it triggered paranoid thinking, the research team injected them with the compound.

The participants were divided into a couple of groups, with two thirds of them receiving an amount of THC similar to that of a strong joint. The other third received a placebo, which like the THC, was injected into the participants to guarantee that those receiving the compound had similar amounts in their blood.

Among those injected with THC, the team reported that its effects lasted for an hour and a half, with approximately half of the participants saying that they experienced feelings of paranoia or paranoid thoughts. Interestingly, 30 percent of the participants receiving the placebo also reported having paranoid thoughts even though the injections they received did not contain THC or any other mood-altering ingredient.

The results also showed that feelings of paranoia began to diminish once the effects of THC wore off and left the body.

The team noted that THC also triggered other negative effects, such as feelings of anxiousness, lowered mood and a negative perception of self, not to mention changes in perception (e.g. noises being louder, colors appearing brighter, losing track of time, etc.)

After the researchers conducted a statistical analysis of the study’s results, they found that the cause of such altered perceptions and negative effects may, in fact, be due to these changed perceptions and negative feelings themselves, which induce feelings of paranoia in marijuana users.

Indeed, the researchers said that the results of the study convincingly prove that marijuana can trigger brief periods of paranoia, which they also believe could explain how the mind incites feelings of paranoia, especially when the user is feeling worried and having negative thoughts or otherwise having altered perceptions that leave them unsettled.

The researchers findings identify several very likely explanations for why the mind encourages paranoid thinking, according to Prof. Freeman. For example, when people are worried, it tends to color their perception of everything around them, causing them to focus on real or imagined threats.

In the same manner, Prof. Freeman notes that just thinking less of ourselves can make us feel more vulnerable to harm – and that even slight changes in our perception can lead us to feel more afraid and suspicious that something bad is going to happen.

He pointed out that spending less time worrying and more time being confident about ourselves will go a long way toward helping us feel less paranoid when we experience altered perceptions that feel unusual to us. In other words, it’s important to not make mountains out of molehills.

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