CANNABIS
Cannabis is a psychoactive drug derived from the Cannabis plant. It has been used for various purposes for thousands of years, including recreational, medicinal, and spiritual uses.
The two primary active compounds in cannabis are delta-9 tetrahydrocannabinol (THC) and cannabidiol (CBD). THC is responsible for the psychoactive effects of cannabis, producing the "high.” CBD, on the other hand, doesn’t produce intoxication but may have potential calming effects and therapeutic benefits.
Cannabis is typically consumed by smoking or vaporizing the dried flowers and leaves of the plant. It can also be consumed orally, such as in the form of edibles, oils, or tinctures.
Effects
Potential positive effects include feeling relaxed, feeling positive, increased sociability, enhanced senses, pain relief, cognitive euphoria, enhanced creativity and increased laughter.
Potential neutral effects include distorted perception of time, enhanced appetite, feelings of body heaviness or lightness, synesthesia (blending of the senses), internal hallucination (“closed-eye visuals”) and changes in libido
Potential negative effects include increased laziness, drowsiness, inability to concentrate, paranoia, anxiety, impaired memory, depersonalisation, impaired motor skills and reaction time, impaired short-term memory fear and confusion
A person may experience physical effects which include changes in blood pressure and heart-rate (elevated when lying down and decreased when standing up), reduction in body temperature, dry mouth, vasodilation (widening of blood vessels which is responsible for reddening of the eyes), changes in blood flow and decreased respiratory rate
Dosage
The dosage of THC to CBD differs lots between different strains and crops of cannabis, which will significantly impact how "high" somebody feels and what kind of experience they have. Furthermore, dosing is affected by an individual's weight, metabolism, tolerance and diet. The many variables that determine the effects of cannabis mean the same doses can have different effects between different people. As a result, when cannabis is in plant form, it is difficult to guide dosing. However, some rough guidelines are outlined below:
For smoked cannabis (via Leafly Dosage Chart): normally when cannabis is in a joint, the dosage ranges from between 0.25-1 grams of dried flower.
For first-time or occasional cannabis smokers, it is recommended that no more than 0.25 grams are added to a joint. As the effects of smoked cannabis begin immediately, it is always better to start with less, and then the user can decide if they would like to smoke any more or not.
For edible cannabis (via Leafly Dosage Chart): Dosage guides are normally given in mg of THC, which is the psychoactive compound in cannabis. The amount of THC per serving of edibles can be found on the label of a product if the cannabis product is shop-bought.
For people making edibles themselves at home with cannabis/THC oils normally, 1g is the same as 1.09g of oil, so the dosage of required THC/cannabis oil can be calculated based on this conversion.
As edibles can have a different and more intense effect than smoking weed, and last much longer, it is essential to start with a lower dose and wait for at least two-hours before eating anymore, as edibles can take a long time to kick in.
THC Dosage
1-2.5mg THC effects can include mild relief for pain, stress and anxiety symptoms and increased creativity. This dosage is recommended for first-time cannabis users and microdosers
2.5-15mg THC can effects include stronger pain relief and decrease in anxiety symptoms, mild euphoria and impaired coordination and perception. This dosage is recommended for standard recreational use and those using cannabis for sleep
30-50mg THC effects can include euphoria and significantly impaired coordination and perception. This dosage is recommended for high tolerance cannabis users
50-100mg THC can effects include significantly impaired coordination and perception and may cause paranoia and possibly nausea. This dosage is recommended for experienced and high tolerance cannabis users and patients with serious condition
Duration
Smoked
Total duration: 1-4 hours
Onset: 10 minutes
Peak: 15-30 minutes
Aftereffects: 45-180 minutes
Edible (Ingested)
Total duration: 4-10 hours
Onset: 20-120 minutes
Peak: 2-5 hours
Aftereffects: 6-12 hours
Dangers
What not to mix with
Alcohol: Alcohol can increase the absorption of THC, meaning smoking cannabis after drinking alcohol causes users to have a more intense experience. Drinking alcohol and smoking cannabis can cause somebody to “whitey”, which is when they experience symptoms including sweating, dizziness, nausea, and vomiting. Increased THC absorption from alcohol also increases the risk of anxiety and paranoia. Furthermore, both cannabis and alcohol impair reaction times and coordination, so having cannabis and alcohol together could increase the likelihood of somebody falling over and injuring themselves.
Classical psychedelics (LSD, psilocybin, etc.): Cannabis and psychedelics synergise with one another, this means the intensity of either drug can increase when they both are taken together. Therefore, using cannabis in combination with psychedelics, could cause unexpectedly strong effects and increase the risk of paranoia and anxiety. Furthermore, using cannabis once the effects from psychedelics have started to wear off, can cause visual hallucinations to reappear - which can be unpleasant for some people if they do not expect this.
Anticholinergic drugs: Taking cannabis and anticholinergic drugs together can cause an interaction that increases the risk of side effects from anticholinergics, such as tachycardia (increased heart rate) and confusion.
Stimulants (e.g. amphetamine and cocaine): Cannabis can increase the action of stimulants. Mixing cannabis and stimulants could increase the tachycardia (increased heart rate), and high blood pressure caused by stimulants, in turn, increasing the risk of a heart attack.
Short term-risks
Experiencing a psychedelic crisis: Although cannabis isn’t a classic psychedelic, THC, especially in edible form, can have profound psychedelic effects which can for some people be unexpected and cause unpleasant adverse effects such as paranoia and anxiety.
Risk of motor vehicle accidents: Cannabis impairs motor coordination and reaction time, and evidence has shown THC decreases driving ability in driving-simulations. One study found cannabis was the most reported illegal drug associated with impaired driving and car accidents, including driving deaths. (9)
Decreased breast milk-production: One experiment found there was a reduced production of the hormone prolactin (required for breast milk production) in a group of women who used cannabis compared to those that didn’t. Therefore, Ingesting cannabis during pregnancy should be avoided.
Ingesting cannabis during pregnancy should be avoided.
NB: For women, smoking cannabis during different stages during the menstrual cycle can have differing effects. For more information here is an article explaining why and how this happens.
Long-term risks
Addiction: Cannabis activates the reward system in the brain. Furthermore, repeated use of cannabis causes tolerance (where it takes a higher dose of the drug to achieve the same effect as when the person first used it). These factors increase the likelihood of becoming addicted to cannabis. One study found that in the United States, 30% of cannabis users could be classified to have a cannabis use disorder. (Study) There is also the risk of nicotine addiction when people are smoking cannabis with tobacco.
Impaired memory: Scientific evidence has suggested that long-term chronic cannabis use can cause memory impairments and other impaired cognitive abilities (problem-solving, learning, etc.) (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5962377/). However, these findings could be affected by other factors such as other substance use, vulnerabilities and IQ.
Psychosis: There has been a link between the use of cannabis and developing psychosis. Cannabis may act as an environmental stressor, meaning it could onset underlying vulnerability to mental health diseases such as schizophrenia. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6058406/) However, the link between psychosis and cannabis-use could also be because those with mental health problems or genetic vulnerability to mental health problems are more likely to smoke cannabis in a chicken and egg scenario.
Cannabinoid Hyperemesis Syndrome (CHS): In rare cases, long-term cannabis use can cause episodes of nausea and vomiting. There usually are 3 phases, first a prodromal phase which includes early morning nausea and vomiting. Secondly, a hyperementic phase which includes ongoing nausea, repeated episodes of vomiting, belly pain, decreased food intake and dehydration. Then finally a recovery phase which can last from days to months where the symptoms go away. As dehydration occurs for a long-time in the hyperementic phase, this can increase the risk of other problems such as muscle spasms or kidney failure. If any symptoms of CHS appear, a medical doctor must be consulted so appropriate symptom treatment can be arranged. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3576702/)
Fertility: One study found that women who used cannabis and tobacco together had a shortened luteal phase during their menstrual cycle, this means there was a decrease in time of the cycle women spent most fertile. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5970012/)
Smoking during pregnancy should be avoided, and if wanting to get pregnant, regular cannabis use may prevent this from happening.
Damage to lung tissue and increased risk of lung cancer: Smoking cannabis and tobacco together increase the risk of damage to the lung tissue caused by smoking and the risk of lung cancer due to the chemicals in tobacco.
How can the risks be minimised?
For first-time users, people may like to take cannabis amongst close friends in a comfortable environment to decrease the risk of anxiety occurring. Focusing on the breath and taking long inhales and exhales can help reduce panic and bring about feelings of calm. Changing the scenery or going on a walk may also help distract the mind from panicking and paranoid thoughts.
Not driving under the influence of cannabis (or any illegal mind-altering substances) will decrease the risk of accidents and death and is very strongly recommended.
Avoiding daily recreational use prevents habits forming and tolerance building. If you find yourself using cannabis every day, it may be a good idea to take regular breaks from use. If you are worried about yourself or a friend being dependent on cannabis, then there are treatment options and helplines available.
Avoiding chronic long-term use of cannabis will decrease the risk of psychosis, memory impairment, CHS and hormonal changes from cannabis use. Also avoiding cannabis strains with high THC levels or “skunk” will decrease the risk of onsetting any psychotic symptoms.
Smoking cannabis through a vaporizer or eating cannabis products is an overall safer method of consumption than in combination with tobacco. Avoiding smoking cannabis with tobacco decreases the risk associated with harmful chemicals in tobacco products, damage to the lung tissue, increased cancer risk and nicotine addiction as a result of cannabis smoking.
What are the potential benefits?
Epilepsy treatment, and seizure reduction (https://www.ncbi.nlm.nih.gov/books/NBK549915/)
Improvement in anxiety and sleep disorder (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6326553/) NB: This study investigates CBD not cannabis
Cancer (increasing appetite and relieving nausea and vomiting from chemotherapy) (https://www.ncbi.nlm.nih.gov/books/NBK224387/)
Reducing muscle spasticity in MS (https://pubmed.ncbi.nlm.nih.gov/29923025/)
Chronic pain (https://pubmed.ncbi.nlm.nih.gov/29923025/)
Web Pages
Leafly is a great information source containing lots of information pages and articles about all aspects of cannabis. For information about specific strains of cannabis, typing the strain name into the search bar will give you information about that strain as well as relevant news articles to that strain: https://www.leafly.com/
Article about dosing and consuming edibles: https://weedmaps.com/learn/products-and-how-to-consume/edibles
Psychonaut wiki for cannabis: https://psychonautwiki.org/wiki/Cannabis
Using cannabis to treat chronic pain conditions and a guide to the best strains for pain relief: https://www.medicalnewstoday.com/articles/322051#how-does-marijuana-work-for-pain
Video explaining how cannabis affects the brain: https://www.youtube.com/watch?v=1mPtbRJ2xro
References
Credit to Dr Andrew Gibson for contributing his medical expertise and background in harm-reduction to the process of making this content.