schrizophenia and marijuana Flashcards
serotonin hypothesis of schizophrenia
-problem in explening auditoriam hallucination
key points :
key points :
1.the psychological effects of LSD and psilocybin are mediatedby the 5-HT receptor
2.5-ht receptor abnormalities are evident in the brains of schizophrenia patients and at-risk patients
- 5-HT receptors antagonism is known to contribute to the effects of atypical antiphycotics
P.E. Bleurler
-coined the term schizophrenia (splitting of the mind)
the split he was trying to describe was not between two personalities
;rather,it was between the various facets of the mind(personality,memory,emotions,perception
schizophrenia
is not dissociative identity disorder
does not have to do with increse of violence
DSM 5 criteria
A. 2 or more of the following
1-delusions
2-hallucinations
3-disorganized speech
4-grossly disgornizedbehaviour
5-negative symptoms
B.the level of imperament is below the level achived prior to the onset
C.continous signs of the disturbance persists for at least 6 months must include at least 1 month of symptoms
E.not attributable to the psysiological effects of a substances
DSM 5 spectrum
(less severe)delusional disorder—brief psychotic disorder—schizophreniform disorder—-schizophrenia—schizoaffective disorder(more severe)
positive symptoms
excess or distortion of normal function
-hallucinations
-delusions
negative symptoms
diminution or loss of normal functions
-flat effect(inability to display emotions)
-avolition(lack of motivation to do tesks)
cognitive impairment
-attetion
-memory
who gets diagnose
-0.5-1.5%
-slightly more common in males
-onset is usually in teens to late 20s
-negative symptoms are more likely in males
-depressive episodes,paranoia delusion and allucination/positive symptoms are more likely in females
genetic risk factors
enviromental risk factors
-maternal infection
-nutrient deficy during pregancy
-obstetric complications
-childhood adversity
-immigrant statues
-urban enviroment
-infection condition
-stressful life event
-cannabis use *
pharmacological treatments
antipychotic drugs
there is usually less luck in treating the negative symptoms of scrizophenia
discovery of anti-psycotics
in 1950,a surgen noticed that the administration of chlorpromazine to his patients to counteract swelling in the brain had a calmin effect
he subsquently suggested that it might have a calming effect on difficult-to-handle patients with psychosis
subsquently reserch showed that,after being administreatred for a period of 2-3 weeks,it alleviated the symptoms of psychosis in many patients
1.dopamine theory of schizophrenia
the theory that schizoprenia is caused by too much activity at receptors for the neurotransmitter dopamine
based on several findings
- brains of individuals with parkison’s disease have marked dopamine depletion;and antipsychotic drugs produce symptoms similar to parkisons ?
- Drugs known to increase dopamine levels (ex:cocain) produce symptoms of schizoprenia
- the efficancy of an antipsychotic drug is correlated with the degree to which it blocks activity at dopamine receptors
problems with dopamine theory
- the newer ‘‘atypical’’ antipsychotic drugs produce a wide variety of changes in the brain and were just as good as tradional antipsychotic
2.it takes 2-3 weeks for antipsychotic drugs to work,yet their effects on dopamine receptor activity are immediate
3.most patients show no significant improvment of the first antipsychotic they are given
2.Glutamatergic hypofunction theory
postulates that the dysfunction of glutamate NMDA receptors on GABAergic interneurons leads to decrease in GABAergic transmission ?
that decrese in inhibition leads to an inbalance of inhibition and excitation?
in scrizophenia is every where in the brain not focus in one location
3.immune dysfunction theory
the theory that schrizophenia is the result of problems with the immune system
based on several findings
1.certain infections increase the risk of psychosis by as much as 60%
2.there is a higher risk of schizophrenia in indivduals with autoimmune diseases
3.several of the gens associated with schizophrenia have immune system functions
4.psychosis is a feature of ‘anti-NMDA receptor encephalities’ an autoimmune disorder in which antibodies attack NMDA type glutamete receptor
3 phases of pychosis
normal
prodrimal
a third develops psychotic
dopamine increses with spychophrenia
incresesed then with helthy individuals striatal dopamine
marijuana
-cannabis sativa
-cannabis indica
-canabis ruderalis
most of the cannabinoids can be found in the leaves and flower
marijuana was used for
-rope
-grains
-and flower were used for the pychoactive and medical effects
marijuana was equivilant to a narcotic
pharmacology
most of its psychoactive effects are attributable to a chemical called THC
but CBD is also very reserched
THC shows mild affinity for the cannabioid receptor:CB1 and CB2
the first endogenous cannabinoid to be discovered was
anandamine
acute psychological effects
lower doses: incresed sense of well-being ,alterations in the perception of space and time,and hightened sensation
higher doses:episodic and working memory impairments,multi-step goal-directed task impairments,speech production impairment
an acute transient psychosis occurs in some individuals-severe paranoia
chronic cognitive effects
-there are few consistent/clear effect on cognition
-effects on working memory function
-rarely presente after 4 to 6 weeks of abstinence
chroninc physiological effects
-both THC and CBD supress tumor cell proliferation
- inhibit synapse formation
-in vitro primates studies have failed to shown any long-term effect of chronic cannabinoid consuption on brain neurichemistry and structure
physilological effects (in humans)
down regulation of CB receptor
half of all gray matter structural imaging studies have found no difference between canabbies users
consistent differences in intermispheric tracts (corpus callosum is smaller)
chronic psychological effects
daily high-potency cannabies use has been associated with:
-incresed risk for psychosis
-earlier onset of psychosis(compared to low potency cannabies)
-CBD similar to atypical antipsychotics
potential for addiction
CUD(cannabis use dissorder)
22% of people that uses
-high potency is associated with 6-7 X incre in risk of cannabis use disorder
atypical psychotics
differ from typical antipsychotic agents in producing significantly fewer extrapyramidal symptoms and having a lower risk of tardive dyskinesia in vulnerable clinical populations at doses that produce comparable control of psychosis.
