Cannabis use precedes the onset of psychotic symptoms in young people
Research: Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10-year follow-up cohort study
2011-03-02
(Press-News.org) 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 today.
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.
So 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."
INFORMATION: END
ELSE PRESS RELEASES FROM THIS DATE:
2011-03-02
Postmenopausal women who smoke or used to smoke have up to a 16% higher risk of developing breast cancer compared to women who have never smoked, finds research published on bmj.com today.
The study also says that women who have had extensive exposure to passive smoking, either as children or in adulthood, may also have an excess risk of developing breast cancer.
While some previous studies have indicated that smoking increases the risk of breast cancer, the theory that passive smoking is also a risk factor, remains controversial.
The researchers, led by Dr Juhua ...
2011-03-02
Have the suspension of central performance management of the 18 week referral to treatment target, and a relaxation of the four hour Accident and Emergency target, changed waiting times asks John Appleby, Chief Economist at the King's Fund in this week's BMJ?
The English National Health Service was once notorious for its excessive waiting times. In December 1999, nearly 160,000 patients were still waiting over six months for their first outpatient appointment and over 50,000 were still waiting over a year for a bed in hospital.
But since 2000, tough targets imposed ...
2011-03-02
In the case of post-traumatic stress disorder, not all symptoms are created equal.
In an effort to better treat PTSD, a study published March 1 in the journal Psychiatric Services is the first to examine which problems associated with PTSD actually correspond to lower quality of life, as indicated by the patient's willingness to die sooner or to risk life-threatening treatment to relieve their symptoms.
PTSD is more costly than any other anxiety disorder. As many as 300,000 veterans returning from Iraq and Afghanistan currently have PTSD, with costs for their care estimated ...
2011-03-02
DARIEN, IL – A new study in the March 1 issue of the journal Sleep indicates that the ability of children with attention deficit hyperactivity disorder to remain vigilant and attentive deteriorated significantly after losing less than one hour of nightly sleep for a week. The study suggests that even moderate reductions in sleep duration can affect neurobehavioral functioning, which may have a negative impact on the academic performance of children with ADHD.
Results of multivariate analyses of variance show that after mean nightly sleep loss of about 55 minutes for ...
2011-03-02
Scientists at the UCSF Cardiovascular Research Institute have discovered how a change in growth hormone activity in mice leads to fatty liver disease, a condition whose human counterpart is of rising concern worldwide.
Disruption of a key protein in the pathway that responds to growth hormone could explain how fatty liver disease develops, the researchers said, but may also offer insights into how our bodies regulate fat in general.
The team's findings and the first reports of a mouse model to study the pathway will appear in the April issue of the Journal of Clinical ...
2011-03-02
LA JOLLA, Calif., March 1, 2011 – When patients receive a bone marrow transplant, they are getting a new population of hematopoietic stem cells. Fresh stem cells are needed when a patient is low on red blood cells, as in anemia, or white blood cells, which can be caused by cancer or even cancer treatments such as irradiation or chemotherapy. The problem is that a bone marrow transplant might not succeed because the transplanted stem cells don't live long enough or because they proliferate too well, leading to leukemia.
To help determine how long a bone marrow (stem ...
2011-03-02
A pioneering program by one of the world's largest cities to switch its vehicle fleet to clean fuel has not significantly improved harmful vehicle emissions in more than 5,000 vehicles – and worsened some vehicles' climate impacts – a new University of British Columbia study finds.
The study – which explores the impacts of New Delhi, India's 2003 conversion of 90,000 buses, taxis and auto-rickshaws to compressed natural gas (CNG), a well-known "clean" fuel – provides crucial information for other cities considering similar projects.
Of the city's more than 5,000 auto-rickshaws ...
2011-03-02
Researchers at Karolinska Institutet have shown in a new study on mice, that cell therapy can be used to reverse the effect of 'bad' LDL cholesterol and reduce the inflammation that leads to atherosclerosis. The new cell therapy, which is presented in the prestigious scientific journal Circulation, can open the way for new therapies for stroke and myocardial infarction if the results prove translatable to humans.
Atherosclerosis is a chronic inflammation of the blood vessels. Cholesterol is transported in the blood in particles called LDL ('bad' cholesterol) that can ...
2011-03-02
A new non-surgical post-mortem technique that has the potential to revolutionise the way autopsies are conducted around the world has been pioneered by forensic pathologists and radiologists at the University of Leicester in collaboration with the University Hospitals of Leicester NHS Trust.
The technique developed by a team in the East Midlands Forensic Pathology Unit, at the University of Leicester, has been published today (1 March) in International Journal of Legal Medicine. This paper presents the development of the methodology and protocol for this technique from ...
2011-03-02
There are already systems that detect ships at sea, but a group of engineers from the UAH, led by the researcher Raúl Vicen, has introduced a new development, involving "the use of artificial intelligence techniques and improvements in the templates used to select input data".
The team has come up with a new detection method "that outperforms the one that has generally been used until now, as well as offering the advantages of low computational costs, and which can also be used in real time".
The new system, the details of which are published in the journal IET Radar, ...
LAST 30 PRESS RELEASES:
[Press-News.org] Cannabis use precedes the onset of psychotic symptoms in young people
Research: Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10-year follow-up cohort study
