Menu
02/03/2011
Cannabis Use Precedes The Onset Of Psychotic Symptoms In Young People
Cannabis use during adolescence and young adulthood increases the risk of psychotic symptoms, while continued cannabis use may increase the risk for psychotic disorder in later life, concludes a new study published on bmj.com.
Cannabis is the most commonly used illicit drug in the world, particularly among adolescents, and is consistently linked with an increased risk for mental illness. However, it is not clear whether the link between cannabis and psychosis is causal, or whether it is because people with psychosis use cannabis to self medicate their symptoms.
A team of researchers, led by Professor Jim van Os from Maastricht University in the Netherlands, set out to investigate the association between cannabis use and the incidence and persistence of psychotic symptoms over 10 years.
The study took place in Germany and involved a random sample of 1,923 adolescents and young adults aged 14 to 24 years. The researchers excluded anyone who reported cannabis use or pre-existing psychotic symptoms at the start of the study so that they could examine the relation between new (incident) cannabis use and psychotic symptoms.
The remaining participants were then assessed for cannabis use and psychotic symptoms at three time points over the study period (on average four years apart).
Incident cannabis use almost doubled the risk of later incident psychotic symptoms, even after accounting for factors such as age, sex, socioeconomic status, use of other drugs, and other psychiatric diagnoses. Furthermore, in those with cannabis use at the start of the study, continued use of cannabis over the study period increased the risk of persistent psychotic symptoms.
There was no evidence for self medication effects as psychotic symptoms did not predict later cannabis use.
These results “help to clarify the temporal association between cannabis use and psychotic experiences,” say the authors. “In addition, cannabis use was confirmed as an environmental risk factor impacting on the risk of persistence of psychotic experiences.”
The major challenge is to deter enough young people from using cannabis so that the prevalence of psychosis is reduced, say experts from Australia in an accompanying editorial.
Professor Wayne Hall from the University of Queensland and Professor Louisa Degenhardt from the Burnet Institute in Melbourne, question the UK’s decision to retain criminal penalties for cannabis use, despite evidence that removing such penalties has little or no detectable effect on rates of use. They believe that an informed cannabis policy “should be based not only on the harms caused by cannabis use, but also on the harms caused by social policies that attempt to discourage its use, such as criminal penalties for possession and use.”
(BMcN/GK)
Cannabis is the most commonly used illicit drug in the world, particularly among adolescents, and is consistently linked with an increased risk for mental illness. However, it is not clear whether the link between cannabis and psychosis is causal, or whether it is because people with psychosis use cannabis to self medicate their symptoms.
A team of researchers, led by Professor Jim van Os from Maastricht University in the Netherlands, set out to investigate the association between cannabis use and the incidence and persistence of psychotic symptoms over 10 years.
The study took place in Germany and involved a random sample of 1,923 adolescents and young adults aged 14 to 24 years. The researchers excluded anyone who reported cannabis use or pre-existing psychotic symptoms at the start of the study so that they could examine the relation between new (incident) cannabis use and psychotic symptoms.
The remaining participants were then assessed for cannabis use and psychotic symptoms at three time points over the study period (on average four years apart).
Incident cannabis use almost doubled the risk of later incident psychotic symptoms, even after accounting for factors such as age, sex, socioeconomic status, use of other drugs, and other psychiatric diagnoses. Furthermore, in those with cannabis use at the start of the study, continued use of cannabis over the study period increased the risk of persistent psychotic symptoms.
There was no evidence for self medication effects as psychotic symptoms did not predict later cannabis use.
These results “help to clarify the temporal association between cannabis use and psychotic experiences,” say the authors. “In addition, cannabis use was confirmed as an environmental risk factor impacting on the risk of persistence of psychotic experiences.”
The major challenge is to deter enough young people from using cannabis so that the prevalence of psychosis is reduced, say experts from Australia in an accompanying editorial.
Professor Wayne Hall from the University of Queensland and Professor Louisa Degenhardt from the Burnet Institute in Melbourne, question the UK’s decision to retain criminal penalties for cannabis use, despite evidence that removing such penalties has little or no detectable effect on rates of use. They believe that an informed cannabis policy “should be based not only on the harms caused by cannabis use, but also on the harms caused by social policies that attempt to discourage its use, such as criminal penalties for possession and use.”
(BMcN/GK)
Related UK National News Stories
Click here for the latest headlines.
27 July 2007
Cannabis 'increases risk of psychotic illness'
Cannabis could increase the risk of developing a psychotic illness, such as schizophrenia, later in life, according to a new study. The study, published in The Lancet, was conducted by Dr Stanley Zammit from Bristol and Cardiff Universities and colleagues at the universities of Bristol, Cambridge and Imperial College London.
Cannabis 'increases risk of psychotic illness'
Cannabis could increase the risk of developing a psychotic illness, such as schizophrenia, later in life, according to a new study. The study, published in The Lancet, was conducted by Dr Stanley Zammit from Bristol and Cardiff Universities and colleagues at the universities of Bristol, Cambridge and Imperial College London.
12 September 2012
Boom In Cannabis Trade Leading To Increase In Gang Violence
A senior police officer has warned of an upsurge in shootings and gang-related violence related to a ‘boom’ in the cannabis trade.
Boom In Cannabis Trade Leading To Increase In Gang Violence
A senior police officer has warned of an upsurge in shootings and gang-related violence related to a ‘boom’ in the cannabis trade.
11 August 2014
Cannabis Factory Uncovered In Cardiff Hospital
Police in Cardiff searching for a missing person have uncovered a cannabis farm in a disused ward of a psychiatric hospital. It is understood that around 30 cannabis plants were uncovered by officers during a search at Whitchurch Hospital in Cardiff. News of the cannabis farm was revealed in a report by the BBC.
Cannabis Factory Uncovered In Cardiff Hospital
Police in Cardiff searching for a missing person have uncovered a cannabis farm in a disused ward of a psychiatric hospital. It is understood that around 30 cannabis plants were uncovered by officers during a search at Whitchurch Hospital in Cardiff. News of the cannabis farm was revealed in a report by the BBC.
28 August 2012
Cannabis Use In Teens Used To Link Drop In IQ
New research finds that persistent cannabis use during adolescence can cause lasting harm to a person's intelligence, attention and memory.
Cannabis Use In Teens Used To Link Drop In IQ
New research finds that persistent cannabis use during adolescence can cause lasting harm to a person's intelligence, attention and memory.
07 May 2008
'U-Turn' As Cannabis Reclassified To Class B
Cannabis has been reclassified as a Class B drug, it has been announced today. In making her decision The Home Secretary Jacqui Smith went against the advice of The Advisory Council on the Misuse of Drugs (ACMD), which wanted to keep it a Class C drug. The council has not been overruled for 30 years.
'U-Turn' As Cannabis Reclassified To Class B
Cannabis has been reclassified as a Class B drug, it has been announced today. In making her decision The Home Secretary Jacqui Smith went against the advice of The Advisory Council on the Misuse of Drugs (ACMD), which wanted to keep it a Class C drug. The council has not been overruled for 30 years.
-
Northern Ireland WeatherToday:A showery start with outbreaks most frequent north of Lough Neagh and through the morning, before dwindling during the afternoon as the northwest breezes ease and brighter spells of weak sunshine prosper. Maximum temperature 8 °C.Tonight:A dry night, save for a few light showers around the coasts, with prolonged clear spells and light winds bringing a frosty dawn for many in central and southern parts. Minimum temperature -3 °C.
