Understanding Depersonalisation and Derealisation
Depersonalisation and derealisation, often abbreviated as DPDR, are clinical conditions characterised by a detached perception of one's surroundings and oneself. Patients frequently describe experiencing a surreal dizziness, feeling as though they're in a dreamlike state.
These symptoms can either manifest episodically or persistently. In severe cases, patients may find themselves unable to feel emotions due to the profound detachment they experience from their environment and their own selves.
Cannabis and DPDR: The Connection
While DPDR can occur in individuals who have never consumed cannabis or any other drugs, a recurring narrative is that this surreal symptomatology first manifested during cannabis consumption and has since persisted. Some patients describe it as a lingering sensation of being "high" long after the actual intoxication has subsided.
Is Cannabis the Culprit?
It is not known whether cannabis causes DPDR or triggers it in people who are already vulnerable, and it has not been established that cannabis only brings out a condition that would have surfaced anyway. For psychosis, a 2019 European case-control study of 901 patients and 1,237 controls found that daily cannabis use, and especially daily use of high-potency cannabis, was associated with higher odds of psychotic disorder. For DPDR, a 2009 survey of 394 adults with the condition found that cannabis was one of the two drugs most commonly reported as precipitating it.
A 2023 systematic review estimated that depersonalisation-derealisation disorder affects around 1% of the general population, with higher rates reported among people with a history of interpersonal abuse. Its onset has been linked to factors such as prolonged stress, traumatic experiences and drug use, including cannabis.
DPDR: A Brain's Protective Mechanism?
Some researchers have proposed that acute DPDR might act as a protective mechanism of the brain, dampening emotional responses to shield it from emotional overwhelm; this remains a hypothesis. The challenge arises when this mechanism overreacts, leading to a prolonged disconnection between the external world and emotional experience.
Under this view, both a traumatic everyday situation and an anxiety-inducing drug effect could activate this response.
Prohibition and Its Consequences
Street cannabis, readily accessible due to bureaucratic challenges associated with prescribed medical cannabis, is unregulated and varies widely in strength. A 2021 meta-analysis found that THC concentrations in herbal cannabis and resin increased over the decades studied, with no evidence of a change in CBD levels.
A regulated market with quality controls could set a THC limit and label CBD content, which may help limit exposure to very high THC levels. However, a 2023 randomised trial in 46 healthy, infrequent cannabis users found no evidence that CBD, at the CBD:THC ratios most common in cannabis products, protected against the acute adverse effects of THC. DPDR often begins in adolescence or young adulthood, a developmental phase for the brain: a study of 204 cases reported a mean age of onset of 22.8 years, with earlier onset associated with greater severity. Supporters of legalisation argue that strict regulation could reduce youth access to cannabis more effectively than current measures.
Addressing DPDR: The Medical Approach
Conventional medicine doesn't yet have an approved medication specifically targeting DPDR symptoms. Occasionally, anxiety-relieving medications like SSRIs are prescribed, as DPDR often coexists with heightened anxiety or depression.
Treatment primarily focuses on psychological approaches, such as cognitive behavioural therapy, although a 2024 systematic review found that studies of DPDR treatments were generally few and of low quality. The primary goal is to divert attention from the symptoms and refocus on other activities, gradually reconditioning the brain to shift its perception.
The Potential of CBD
It has been suggested that CBD might lessen some short-term effects of THC or be relevant to DPDR, but neither has been established, and the 2023 trial described above found no protective effect against THC's acute effects. CBD has been studied for possible anxiety-reducing and antipsychotic effects: a 2015 review described the human evidence on anxiety as limited to short-term studies with few clinical populations, and a 2020 systematic review found limited evidence of antipsychotic efficacy. Increased anxiety is a central amplifier of DPDR symptoms.
Fear of the symptoms can create a vicious cycle, perpetuating them. Research on CBD and DPDR is very limited. A small 2011 study in ten healthy male volunteers found only a non-significant trend for CBD to reduce depersonalisation induced by the drug ketamine, and it did not include people with DPDR.
