Many people aren't convinced that cannabis addiction exists, yet research is beginning to show that it is indeed possible to experience withdrawal symptoms when getting off the pot. Fortunately, these tend to be significantly milder and shorter-lasting than with other drugs – the most common symptoms being anxiety, irritability, loss of appetite, and strange dreams.
Numerous drugs interfere with dopamine signalling within the brain’s reward circuit when abused, resulting in a downregulation of dopaminergic neurons. As a result, frequent users often develop depression and a reduced ability to experience pleasure after quitting substances like heroin and cocaine.
Luckily, research has indicated that cannabis does not reduce the availability of dopamine neurons, even in heavy users, meaning that those who get high on a daily basis are unlikely to experience the emotional lows that other drug users might suffer from when trying to quit. However, blunted dopamine signaling has been observed in chronic weed smokers, indicating that some degree of affective distress is to be expected when giving up the drug.
Furthermore, repeated ingestion of cannabinoids like THC is known to downregulate vital cannabinoid receptors in the brain. In particular, the CB1 receptor – the main target for a neurotransmitter called anandamide – becomes less available in heavy cannabis users.
An endocannabinoid, anandamide is sometimes referred to as the "bliss molecule" due to its ability to generate a sense of euphoria. Therefore, downregulation of CB1 receptors results in a reduced capacity to simply get high on life, which can be a major problem for frequent cannabis users once they quit.
The good news, however, is that this CB1 deficiency is typically restored within four weeks of quitting weed, so these withdrawal symptoms are unlikely to persist for too long.
Generally, the first week after quitting is thought to be the hardest. According to several studies, people with problematic cannabis use normally start to experience an increase in anxiety and irritability within a day or two of giving up, but this typically begins to subside after four days, returning to baseline after a week or two.
Other symptoms such as difficulty sleeping and strange, vivid dreams, however, have been found to become increasingly severe for about nine or ten days, at which point they reach their peak. These somewhat unsettling phenomena appear to persist for quite some time, with some studies indicating that they don’t return to baseline even after six weeks.
It’s worth mentioning that such withdrawal symptoms are only likely to affect people with problematic cannabis use, such as those who have consumed the drug on a daily basis for many years and have developed a dependency upon it. Smoking the odd joint or getting high on a space cake every now and then is not going to lead to any withdrawals – although it’s always a good idea to inform oneself of the risks associated with substance use and to enjoy everything in moderation.