Psychoactive THC in Cannabis

Delta-9-THC Is Not as Harmless as You May Think

Young teenagers smoking marijuana which contains THC
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THC stands for delta-9-tetrahydrocannabinol or Δ-9-tetrahydrocannabinol (Δ-9-THC). It is a cannabinoid molecule in marijuana (cannabis) that's long been recognized as the main psychoactive ingredient—that is, the substance that causes users to experience the marijuana high.

THC is just one of more than 400 different active substances—and 60 different cannabinoid molecules—contained in marijuana, although THC is the most recognized. Another important cannabinoid molecule that has received major interest is cannabidiol (CBD).

How THC Works

THC works by attaching to cannabinoid receptors, which are found throughout the brain and nervous system. THC can be detected in the body much longer than most other drug compounds (up to 20 hours after ingestion), although the psychoactive effects only last for a few hours.

THC is also stored in body fat and organs for three to four weeks. Hair follicle testing may identify THC after even longer periods of time, around 90 days. Urine testing is often used but has been found to be an unreliable method of detection.

Amount of THC in Marijuana

We're definitely not dealing with the same pot as we were in the past. This is because today's marijuana is much more potent, with THC levels averaging 9.6%, according to the National Institute on Drug Abuse (NIDA). By comparison, in the early 1990s, marijuana generally had a THC level of about 4%.

The strength of modern "high-potency" strains of marijuana, such as sinsemilla ("skunk") was reportedly at least four times as strong, containing about 15% THC. The amount of THC contained in marijuana varies by the the way that cannabis is prepared for use, such as leaf/bud, hashish, or hashish oil. THC levels can exceed 50% in products made from marijuana extracts.

Is Delta-9 THC Addictive?

Cannabis is the most common substance abused in the United States, after alcohol and tobacco. Despite the belief by many chronic cannabis users that the drug is not addictive, THC tolerance and dependence have been widely documented in various studies.

According to the NIDA, about 30% of people who use marijuana will become addicted—and using the drug prior to age 18, when your brain is still developing, increases the likelihood of a marijuana use disorder four- to seven-fold. Similar to other types of addiction, marijuana use disorder involves a preoccupation with the drug, bingeing, and symptoms of withdrawal when you can't use the drug.

Risks of THC

There is considerable research evidence that THC is associated with increased risk of developing psychosis, particularly among adolescents. It is also linked to increased anxiety, learning impairment, and decreased memory formation.

CBD, on the other hand, has been found to counter those effects, reducing anxiety, improving learning ability, and working as an antipsychotic, although much of the research is on animals. When taken together, as is the case with marijuana use, CBD seems to reduce the negative effects of THC.

A 2013 meta-analysis, which is a type of study that combines the results of many previous studies, found some evidence that THC may be neurotoxic. There are differences in the brain structure of chronic marijuana users who do not have psychosis.

One interesting point underscoring the brain changes: While there is a reduction in gray matter volume in the prefrontal cortex in chronic users, there is an apparent compensatory response. There is a subsequent increase in the density of fibrous connections among remaining neurons, which may cancel out some or all of the neurotoxicity. 

Research into the effects of THC (or delta-9-THC) is complicated by many factors, but there is sufficient evidence that THC can be harmful, particularly to younger people whose brains are still developing. They should, therefore, avoid frequent use of marijuana.

THC in CBD Products

With the popularity of CBD, there has been a major market shift toward CBD products. Some of these may contain traces of THC (around 0.3% to 0.9%), depending on how they're formulated.

This small concentration is highly unlikely to result in a feeling of high, and some experts argue that the effectiveness of CBD is potentiated by small amounts of THC. However, if you're looking for a CBD product without any THC, be sure to seek out a source that uses third-party testing to certify the purity of the product.

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