Cannabis use and psychiatric disorders.
B. Issa
Neurosciences 2007 DOI: 10.17712/1658-3183.1520 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Review Peer reviewed |
|---|---|
| Topics | Cannabis |
| Key findings | The review states that cannabis use is associated with several psychiatric problems, including anxiety, mood, and adjustment disorders and psychosis such as schizophrenia. It describes delta-9-THC as the principal psychoactive component, converted to the more psychoactive metabolite 11-OH-9-THC, and acting on CB receptors concentrated in the basal ganglia, hippocampus, cerebellum, and cerebral cortex but absent from the brain stem. |
Abstract
Cannabis is one of the oldest, and one of the most widely abused substances. It is available in all parts of the world where it is used commonly as a recreational drug when smoked or consumed in some other ways. It also has some medicinal potential, the reason for which some are calling for its legalization. Cannabis has been associated with several psychiatric problems such as anxiety problems, mood disorders, adjustment problems, acute organic problems, and psychosis such as schizophrenia. The link between these problems is highlighted in this short review. Pharmacology. The principal component of cannabis is delta-9-Tetrahydocannabinol (∆-9-THC). The plant, however, contains more than 400 chemicals, of which 60 are chemically related to ∆-9-THC. In humans, ∆-9-THC is rapidly converted to 11-hydroxyl delta-9THC, the metabolite that is active in the central nervous system. 11-OH-9-THC is approximately 3 times more psychoactive. Oral cannabis is very powerful, almost psychedelic. The receptor for cannabinols is known as the cannabinoid (CB) receptor. It is a member of the G-protein linked family receptors. The CB receptor is linked to the inhibitory G-protein (Gi), which is linked to adenyl cyclase in an inhibitory fashion. The receptor abounds in the basal ganglia, hippocampus, cerebellum, and cerebral cortex. The brain stem does not have the receptors, hence, there is little effect of cannabis on the respiratory and cardiovascular systems. Human response to cannabis. Many variables affect the psychoactive properties of cannabis. These include: the potency of the cannabis used (as described above), the route of administration, the smoking technique, the dose, the user’s experience, and expectation, and the biological vulnerability of the user. Cannabis induces a state of intoxicated relaxation, euphoria, and dreaminess. It is quick acting. Smoked, the first effects are usually felt within seconds. The peak follows within minutes and then declines sharply after approximately 55 minutes, with a 90 minute tail-off. Cannabis produces a general sense of well-being, relaxation, and euphoria. Introspective dreaminess, increased appreciation of music, sleepiness, and time distortion is often felt by the user. The effects, however, can be subtle. The first time user often detects little or no effect. Cannabis increases heart rate but decreases blood pressure. At high doses, orthostatic hypotension may appear. Increased appetite (munchies) and dry mouth are other effects of cannabis and may indicate intoxication. It dilates the conjunctival blood vessels (blood shot eyes, red eye) and may impair short-term memory.
Comparable studies
Other narrative reviews on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Causal association between cannabis and psychosis: examination of the evidence | 2004 | Review | |
| Cannabis sativa: A comprehensive ethnopharmacological review of a medicinal plant with a long history. General (historical and pharmacological review) | 2018 | Review | |
| Psychiatric effects of cannabis | 2001 | Review | |
| Beyond THC: The New Generation of Cannabinoid Designer Drugs | 2011 | Review | |
| Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug | 2006 | Review |