Podcast
Questions and Answers
What technique did Laruelle et al. utilize to estimate dopamine release in individuals with schizophrenia?
What technique did Laruelle et al. utilize to estimate dopamine release in individuals with schizophrenia?
What was the significant finding of Laruelle et al. regarding dopamine release in individuals with schizophrenia after amphetamine injection?
What was the significant finding of Laruelle et al. regarding dopamine release in individuals with schizophrenia after amphetamine injection?
Which of the following is NOT an indirect index used to measure dopaminergic activity according to the content?
Which of the following is NOT an indirect index used to measure dopaminergic activity according to the content?
What relation was observed between dopamine release and positive symptoms in individuals with schizophrenia?
What relation was observed between dopamine release and positive symptoms in individuals with schizophrenia?
Signup and view all the answers
Why is measuring dopamine levels directly in humans not possible?
Why is measuring dopamine levels directly in humans not possible?
Signup and view all the answers
What is the adjusted odds ratio for daily use of 'skunk-like' cannabis in relation to psychotic disorders?
What is the adjusted odds ratio for daily use of 'skunk-like' cannabis in relation to psychotic disorders?
Signup and view all the answers
Which of the following risk factors is associated with the highest risk for developing schizophrenia?
Which of the following risk factors is associated with the highest risk for developing schizophrenia?
Signup and view all the answers
Which risk factor is considered an intermediate factor for psychotic disorders?
Which risk factor is considered an intermediate factor for psychotic disorders?
Signup and view all the answers
What is the odds ratio for cannabis use as a risk factor for schizophrenia?
What is the odds ratio for cannabis use as a risk factor for schizophrenia?
Signup and view all the answers
According to the comparison, which risk factors are linked to conception and the perinatal period?
According to the comparison, which risk factors are linked to conception and the perinatal period?
Signup and view all the answers
Which type of cannabis has been linked to the highest risk of psychotic disorders according to the study?
Which type of cannabis has been linked to the highest risk of psychotic disorders according to the study?
Signup and view all the answers
What is the relative risk of being an offspring of an immigrant from selected countries in relation to developing schizophrenia?
What is the relative risk of being an offspring of an immigrant from selected countries in relation to developing schizophrenia?
Signup and view all the answers
Which of the following reflects a low-risk factor for schizophrenia?
Which of the following reflects a low-risk factor for schizophrenia?
Signup and view all the answers
Which variant of the COMT gene is associated with a higher risk of developing schizophrenia in individuals who used cannabis during adolescence?
Which variant of the COMT gene is associated with a higher risk of developing schizophrenia in individuals who used cannabis during adolescence?
Signup and view all the answers
What type of research design did Caspi et al. (2005) utilize to demonstrate the effects of cannabis use and genetic factors on adult psychosis?
What type of research design did Caspi et al. (2005) utilize to demonstrate the effects of cannabis use and genetic factors on adult psychosis?
Signup and view all the answers
According to Estrada et al. (2011), how is the timing of cannabis use related to the onset of schizophrenia-spectrum disorders?
According to Estrada et al. (2011), how is the timing of cannabis use related to the onset of schizophrenia-spectrum disorders?
Signup and view all the answers
What does the research suggest regarding the effects of cannabis use on individuals with different COMT genotypes?
What does the research suggest regarding the effects of cannabis use on individuals with different COMT genotypes?
Signup and view all the answers
What is one hypothesis suggested by Estrada regarding the effects of cannabis on young patients?
What is one hypothesis suggested by Estrada regarding the effects of cannabis on young patients?
Signup and view all the answers
What did the results of the studies by Caspi et al. and Estrada et al. primarily focus on?
What did the results of the studies by Caspi et al. and Estrada et al. primarily focus on?
Signup and view all the answers
Which of the following outcomes is suggested to correlate with the COMT Val158Met genotype according to research?
Which of the following outcomes is suggested to correlate with the COMT Val158Met genotype according to research?
Signup and view all the answers
What implication does the research suggest about cannabis sensitivity during adolescence?
What implication does the research suggest about cannabis sensitivity during adolescence?
Signup and view all the answers
Which of the following drugs is known to stimulate the synthesis of dopamine?
Which of the following drugs is known to stimulate the synthesis of dopamine?
Signup and view all the answers
What increases as a result of chlorpromazine administration according to Carlsson & Lindqvist's findings?
What increases as a result of chlorpromazine administration according to Carlsson & Lindqvist's findings?
Signup and view all the answers
What does the dopamine hypothesis suggest is the cause of positive symptoms in schizophrenia?
What does the dopamine hypothesis suggest is the cause of positive symptoms in schizophrenia?
Signup and view all the answers
What was the main conclusion regarding potent anti-schizophrenic drugs and their action?
What was the main conclusion regarding potent anti-schizophrenic drugs and their action?
Signup and view all the answers
What did Snyder demonstrate about the binding of drugs to D2 receptors?
What did Snyder demonstrate about the binding of drugs to D2 receptors?
Signup and view all the answers
Which of the following statements best describes chlorpromazine's mechanism of action?
Which of the following statements best describes chlorpromazine's mechanism of action?
Signup and view all the answers
What was a significant gap in the early version of the dopamine hypothesis?
What was a significant gap in the early version of the dopamine hypothesis?
Signup and view all the answers
What is a common feature of ineffective agents in relation to dopamine receptors?
What is a common feature of ineffective agents in relation to dopamine receptors?
Signup and view all the answers
What is the primary cause of positive symptoms of schizophrenia according to the dopamine hypothesis?
What is the primary cause of positive symptoms of schizophrenia according to the dopamine hypothesis?
Signup and view all the answers
What compound was discovered by Henri Laborit that initially showed anti-anxiety effects?
What compound was discovered by Henri Laborit that initially showed anti-anxiety effects?
Signup and view all the answers
Which of the following statements is true about chlorpromazine?
Which of the following statements is true about chlorpromazine?
Signup and view all the answers
What was a key finding of Ehringer and Hornykiewicz in 1960 regarding Parkinson's disease?
What was a key finding of Ehringer and Hornykiewicz in 1960 regarding Parkinson's disease?
Signup and view all the answers
What effect do dopamine agonists have on the positive symptoms of schizophrenia?
What effect do dopamine agonists have on the positive symptoms of schizophrenia?
Signup and view all the answers
What type of symptoms did chlorpromazine primarily reduce in patients with schizophrenia?
What type of symptoms did chlorpromazine primarily reduce in patients with schizophrenia?
Signup and view all the answers
What is a limitation of the dopamine hypothesis regarding schizophrenia?
What is a limitation of the dopamine hypothesis regarding schizophrenia?
Signup and view all the answers
Reserpine was discovered to be effective as an anti-schizophrenic agent from which plant?
Reserpine was discovered to be effective as an anti-schizophrenic agent from which plant?
Signup and view all the answers
Study Notes
Cannabis Use and Schizophrenia
- Cannabis use during adolescence is associated with an increased risk of developing schizophrenic-type disorders for individuals with the Val variant of the COMT gene.
- Individuals with the Met variant of the COMT gene are not affected by cannabis use.
- The earlier someone first used cannabis, the earlier the age of onset of schizophrenia-spectrum disorder.
- The COMT Val158Met genotype modulates the association between cannabis use and the age at onset of schizophrenia-spectrum disorders.
- Val/Val genotype carriers have an earlier age at onset of disorder than Met carriers.
Risk Factors for Schizophrenia
-
Highest Risk Factors
- Having a first-degree relative with schizophrenia (mother, father, sibling).
- Being the offspring of an immigrant from selected countries.
-
Intermediate Risk Factors
- Having antibodies to Toxoplasma gondii.
- Being an immigrant from selected countries.
- Being raised in an urban area.
- Being a cannabis user.
- Having minor physical anomalies.
- A father over 55 years old.
-
Low Risk Factors
- Head injuries in early childhood.
- Obstetrical complications.
- Having a father 45 or older.
- Specific common genetic polymorphisms.
- Birth seasonality.
- Maternal exposure to influenza.
- Extreme prenatal stress.
Dopamine Hypothesis of Schizophrenia
- The dopamine hypothesis explains positive symptoms of schizophrenia as being caused by an excess of dopamine in the mesolimbic pathway.
- Chlorpromazine, an effective anti-psychotic agent, was discovered to block dopamine receptors.
- Drugs like cocaine, amphetamine, methylphenidate (block reuptake of DA) and L-DOPA (stimulates synthesis of DA) reproduce positive symptoms of schizophrenia.
- Anti-psychotic drugs alleviate these positive symptoms.
- Chlorpromazine increases the level of dopamine metabolites and therefore reduces the amount of dopamine available at the synapses.
- The potency of drugs like haloperidol as anti-schizophrenic agents is directly related to their affinity to D2 receptors.
- The dopamine hypothesis has evolved to incorporate genetic and neurodevelopmental factors.
Evidence of Abnormalities in DA Transmission
- Dopamine levels cannot be measured directly in humans.
- There is evidence of increased dopamine release in the striatum of individuals with schizophrenia.
- Amphetamine causes greater dopamine release in the striatum of those with schizophrenia versus controls.
- Individuals with greater amounts of dopamine release experience greater increases in positive symptoms.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz explores the complex relationship between cannabis use and the onset of schizophrenia, particularly focusing on the role of the COMT gene variants. It discusses how genetic factors and early cannabis exposure correlate with schizophrenia risk, alongside various environmental factors that may contribute to this disorder.
