Cannabis and Psychosis Flashcards
What is the greatset health concern with the use of Cannabis?
Development of psychotic disorders
What is the increase that studies have shown with regulat cannabis use in adolesecence?
A twofold increase in the risk of psychosis.
Do the majority of people who have used cannabis develop a psychotic disorder?
No.
Is cannabis sufficient to cause schizophrenia?
No.
Can cannabis use contribute the risk of the development of a psychotic disorder in vulnerable individuals?
Yes.
What percent of people worlwide have schizophrenia? When does its onset occur?
1 percent. Occurs in late adolescence or early childhood.
What can THC produce?
Transiet, acute, but mild psychoti experiences
What did a study show with people who are diagonosed with schizophrenia?
Cannabis use increased cognitive function.
What is the big question with cannabis?
Does it increase the risk of later development of schizophrenia and other psychoactive disorders? In particular, adolescences.
What can elicit paranoid psychosis?
Cannabis intoxiciation (THC in particular)
What did Jacques-Joseph Moreau report in 1845 about hashish?
That it could induce “acute psychotic reactions, generally lasting but a few hours, but occasionally as long as a week”.
What was related to the reaction?
Dosage.
What is the main features of the acute psychotic reactions?
Paranoid ideation, illusions, hallucinations, delusions, depersonalization, confusion, restlessness and excitement.
What is an enzyme that metabolizes dopamine in the prefrontal cortex?
Catechol-O-methyl transferase (COMT)
What occurs in individuals with the Val/Val genotype for COMT?
They have a higher metabolic activity of that enzyme than inidividuals with the Met/Met polymorphism.
Patients who have overactive enzyme are what for the valine form? What does it do?
Homozygous. It renders COMT hyper-efficient and may result in dopamone deficiency.
What happens in the genotype Met/Met?
Results in hypo-active enzyme and causes excessive dopamine in the synaptic cleft.
What did the Henquet and colleagues discover with the effects of the interaction of COMT polymorphism and a trait index of psychotic liabilit of smoked THC?
Indivuals with Val/Val polymorphism and high scores on psychosis liability had higher THC induced psychotic symptoms than individuals with the Met/Met polymorphism
What have several studies shown with the association between cannabis use in adolescence?
Development of schizophrenia, the risk increasing with higher frequency of cannabis.
What did the study show in the link between frequency of cannabis use and psychotic diagnosis?
A dose response relationship was observed between self-reported cannabis use by age 18 and psychiatric hospitalization for schizophrenia by age 45, with a three-fold increase in risk in those who used cannabis more than 50 times by age 18.
What is important to note in this study of the link between frequency and cannabis use and psychotic diagonisis?
Among 50,000 individuals in this initially very large sample only 362 (0.72%) were later hospitalized for schizophrenia.
What age confers greater risk for schizophrenia?
Early cannabis use (before age 15) than later cannabis use (by age 18).
Does cannabis cause schizophrenia?
No.
What has been show with use of cannabis during adolescence?
Greater risk of psychosis
