Cannabis

Cannabis is a general term used for various preparations derived from the hemp plant (Cannabis sativa). “Marijuana” refers to the dried flowers, and “hashish” refers to the dried resin or pressed resin of the cannabis plant. [1] [2]

The intoxicating effect of cannabis arises from cannabinoids. The most significant of these is delta-9-tetrahydrocannabinol (THC), which is found most abundantly in the plant’s flowers. [1] [3] In Finland, cannabis is mainly used by smoking, and occasionally by vaporizing. Eating or drinking cannabis is less common. [4]

Legal status: Cannabis and THC are classified as narcotics in Finland. Its use, purchase, sale, and possession are prohibited. [5] [6]

How does it work?

The psychoactive substance in cannabis, THC, binds to cannabinoid receptors found in both the brain and peripheral nervous system. [1] [3] [2] Its effect on the central nervous system is mainly depressant. [7] When smoked or vaporized, the effect begins immediately and lasts a few hours. [1] [8] When ingested, the onset is slower and the duration is longer. [8]

A large portion of THC is stored in body fat and is released slowly. If the substance has been used heavily, THC can remain in the body for a couple of weeks. However, the quantities released from fat are so small that they do not cause intoxication.

The effects of cannabis vary depending on the method of use, preparation, plant strain, usage context, and the user’s personal sensitivity and experience. Dosage also has a significant impact. [1] [2] [8] [9]

Desired effects: Cannabis has both stimulating and calming effects: it typically reduces aggression and promotes relaxation, while also stimulating thought processes and enhancing sociability. It alters perception of time and space. [1] [2] [8] [12] It heightens the senses and may increase appetite. At high doses, mild hallucinations may occur. [1] [2] [9]

Side effects: Cannabis impairs working memory, attention, motor coordination, and reaction speed. [1] [2] [9] [12] Unpleasant experiences such as anxiety and paranoia are common. [2] [9] The user may feel restlessness, fear of death, or fear of losing control. [2] Cannabis can lower body temperature and increase heart rate and blood pressure. The eyes may redden, and the mouth may feel dry. [1] [2] [9]

Key risks

Acute risks: During cannabis intoxication, attention and reaction speed are significantly impaired, increasing the risk of accidents, especially in traffic. [1] [8] [9]

Cannabis use can lead to psychotic symptoms and may even trigger a psychosis. The risk increases with early initiation, high THC content, genetic predisposition, and trauma history. [2] [12] [13] [14]

Cannabis is not associated with fatal poisoning or overdose, but it can be a contributing factor in deaths involving diagnosed or undiagnosed heart conditions. [9] [10] [11] *

Polydrug use risks: Cannabis has a depressant effect on the central nervous system, [7] so combining it with other depressants can increase the risk of unconsciousness and accidents.

Heavy use risks: Long-term cannabis use impairs cognitive functions, especially verbal learning, memory, and attention. [8] The effect is especially pronounced if use begins at a young age. [8] [14] [15] Early initiation may also cause permanent changes in brain structure. [15] Cannabis use among youth has been associated with apathy, lack of motivation, and poor academic or work performance. [2] [9] [17]

Prolonged use may also increase the risk of anxiety disorders, depression, and schizophrenia. [14] [16] The risk of schizophrenia is significantly higher if cannabis use begins in youth. [16] There is some evidence that heavy cannabis use negatively affects the immune system, sexuality, and reproduction, though results are somewhat conflicting. [8] [1]

If smoked, cannabis causes long-term harm similar to that of tobacco. [1] [2]

Dependence: Cannabis can cause psychological dependence with repeated and long-term use. Tolerance also increases with continued use. [18] Withdrawal symptoms from heavy use may include irritability, anxiety, craving, sleep disturbances, depressed mood, restlessness, muscle aches, and loss of appetite. [1] [18] Symptoms appear 1–2 days after cessation and may last 10–14 days. [2]

Use during pregnancy: Cannabis use during pregnancy is risky. [9] If used with tobacco, the risks and harms to the fetus are similar to those of smoking. [1]

How can risks be reduced?

Driving under the influence of cannabis must be strictly avoided, as it impairs time perception and significantly slows reaction time. [1] [8] [9]

To prevent long-term harm, cannabis use should be avoided during adolescence when the brain is still developing. Especially those with a family history of mental illness should abstain from trying or using cannabis. Harms can also be reduced by limiting both the quantity and frequency of use, which in turn helps avoid dependence and withdrawal symptoms.

Risks to the respiratory system and cancer can be avoided by not smoking cannabis. [2]

However, it must be remembered that all substance use is inherently risky. Harm reduction strategies can never eliminate these risks entirely. People also react very differently to the same substances and doses, which should always be considered when it comes to cannabis.