Presentation is loading. Please wait.

Presentation is loading. Please wait.

Cannabis and Mental Health

Similar presentations

Presentation on theme: "Cannabis and Mental Health"— Presentation transcript:

1 Cannabis and Mental Health
4/14/2017 Cannabis and Mental Health Sir Robin M Murray, FRS Institute of Psychiatry, London UK 1

2 Most people who use cannabis don’t develop problems

3 No of times cannabis taken
Swedish Army Study of Andréasson et al 1987 Cannabis Use Psychosis Cases of Sz per 1,000 1 2 10 <50 >50 30 20 No of times cannabis taken Longitudinal Studies Risk of schizophrenia-like psychosis at age 26 years Country Sweden NL NZ (Chr) NZ (Dun) Germany UK Australia n 50,053 4,045 18,000 1,265 1,253 2,436 8,500 3,800 FU 25 yrs 3 yrs Retro 15 yrs 4 yrs 18 mths 14 yrs OR 3.1 2.8 12.0 3.2 1.8 1.7 1.5 2.2 Arseneault et al 2002 Odds ratio

4 The ingredients of cannabis
Tetrahydrocannabinol (THC) – partial agonist at CB1 High doses cause impairment of attention, memory and learning, hallucinations and paranoid ideas Cannabidiol (CBD) – inverse agonist at CB1 Is not hallucinogenic Has anxiety relieving properties Antagonises effects of THC THC CBD

5 The ingredients of cannabis
THC causes Impairment of attention, memory and learning Hallucinations and paranoid ideas Cannabidiol (CBD) Is not hallucinogenic Has anxiety relieving properties Antagonises effects of THC THC CBD

6 Cannabis potency in England
Skunk THC content (%) 2 4 6 8 10 12 14 1995 1996 1997 1998 1999 2000 2001 2002 2004 Imported Herbal Resin 2008 Potter et al 2008, DoH, 2008

7 OR Risk of being a Psychotic Case
(OR adjusted for gender, age, ethnicity, Stimulants, level of Ed) OR

8 Why do only some cannabis users go psychotic?
As we have seen, the study of GxE is in its very early stages. I outlined steps we have adopted to conduct this research. Important to step back and ask, why is it useful to do GxE studies? What are the promises of this research? First, Implications for neuroscience. Psychosis Vulnerability

9 The major unresolved issue concerns cognition
Lots of studies show that heavy cannabis users have impaired cognition Some studies show that prolonged abstinence improves most of what has been lost Last year follow-up of the Dunedin cohort reported that those who had started using cannabis as adolescent had lost 8 points of IQ by 38 years

Download ppt "Cannabis and Mental Health"

Similar presentations

Ads by Google