LC4 - psychosis

Question 1

symptoms

Answer 1

o Delusions (+ sympt)
o Hallucinations (+ sympt)
o Disorganised speech
o Catatonic and disorganised behaviour
o Negative symptoms
 Affective flattening
 Alogia
 Avolition
- Social occupational dysfunction  one or more major areas of functioning are markedly below achieved level prior to onset op disturbances (or to what is to be expected)
- Duration  at least 6 months
- Psychosis = expression of positive symptoms
- Schizophrenia is positive + negative symptoms in a chronic manner

Question 2

+ and - symptoms

Answer 2

• Positive:
  o Delusions
  o Hallucinations
  o Language distortions
  o Disorganised behaviour
  o Catatonic behaviour
  o Agitation
   Executive functions affected
• Goal-driven behaviour
• Attention
• Learning
• Problem solving
• Negative
  o Blunted affect
  o Emotional withdrawal
  o Passivity
  o Difficulty abstract thinking
  o Alogia
  o Avolition
  o Anhedonia

Question 3

SZ development

Answer 3

• Starts in early adulthood  psychotic breakdowns until medication management is ptimized later in life
• Cognitive decline occurs throughout the course of disease until a steady state is reached around 30 where people can normally not function independently
  o Some can function quite well
• 17.5% of people have some broad expression of symptoms  without major dysfunction so symptoms and disorders are on a continuum
• Identifying people in the prodromal phase is possible
  o Some combination of (preclinical) symptoms that predicts that 16%-25% of those people will have a major psychotic episode (ultra high risk group) or other mental health dysfunction

Question 4

risk factors

Answer 4

• Everyone deals with stressors that induce subclinical schizotypal symptoms during adolescence
  o This is resolved in low-risk people
  o Genes and environmental factors can induce further development of schizophrenic symptoms  the factors also do not work independently

 Large cerebral ventricles
 Urbanicity
 Immigrant population
 Birth issues
 Early life infections
 Cannabis use
* OR increases when THC content increases and when use frequency increases and younger use is worse (meaning that it is not the case that the schizo-related genes make you smoke more weed)
* Not genetic confounding
 Childhood trauma
* Fear
* Bullying
* Discrimination  immigrant population as minority  social defeat  Schizo development

• Sensitisation to repeated trauma/stressor –> more sensitive and more likely to have a severe schizotypal response that might develop into schizoaffective disorders

Question 5

genetics SZ

Answer 5

• 1st degree SZ relative  RR= 10
  o Much higher than the environmental factors
• GWAS –> 108 loci found
  o Brain & Immune System
  o Genes related to:
   glutamate signaling (synaptic plasticity)
   calcium channels
   D2 receptor
  neurodevelopment!!
  affective genes!!!

Question 6

symptom domains and brain areas

Answer 6

• Symptom domains might be matched to malfunctioning brain regions
  o Positive symptoms  mesolimbic
  o Negative symptoms  mesolimbic + PFC + reward system (NaC)
  o Cognitive  dlPFC
  o Aggressive  amygdala + OFC
  o Affective  vmPFC

Question 7

DA pathways

Answer 7

• Nigrostriatal pathway  movement control
  o SN  striatum
• Mesolimbocortical pathway  reward, cognition, motivation
  o VTA  NaC
  o VTA  DLPFC and VMPFC

Question 8

DA in psychosis

Answer 8

• DA hypothesis of psychosis and SZ
  o Hyperdopaminergia in the (ventral) striatum (i.e. NaC)
   Positive symptoms
  o Hypodopaminergia in the PFC
   Negative symptoms
   Executive and cognitive dysfunction
• Its not dysfunction of the tegmentum DA neurons but more likely dysfunction of neurons that have higher input on these DA neurons
  o Hippocampus
  o Lateral septum
  o PFC
• DA is involved in attributing meaning/valence to stimuli which is needed for correct reward prediction and salience attribution
  o Rewarding, punishing, novel stimuli that need to be remembered in working memory for executive processing
  o Dysfunctional DA system  misrepresentation of the (social) world