Chapter 8: Schizophrenia Flashcards
define schizoaffective disorder
mix of schizophrenia (delusions, hallucinations, disorganized speech, negative symptoms) with mood disorder usually major depressive or manic episode
what makes schizoaffective disorders differ from mood disorder with psychotic features
must have at least 2 weeks of hallucinations or delusions WITHOUT mood symptoms
schizophreniform disorder
meet criteria A,D,E of schizophrenia diagnosis but symptoms are only for 1-6 months
- 2/3 will later meet requirements of schizophrenia or schizoaffective disorder
- can have confusion but not blunted or flat affect
brief psychotic disorder
- sudden onset of delusions, hallucinations, disorganized speech or behavior. lasts for 1 day - 1 month and symptoms remit
- can occur after major stressor (accident or childbirth) while others happen with no apparent stressor
Delusional disorder
delusions lasting 1 month that pertain to real life (deceived by spouse, being followed)
- less common 0.05-0.2% prevalence
- dont have any other psychotic symptoms
- mean onset is 40 yrs old but ranges from 18-90
- men: persecutory and jealous subtype
- women: erotomanic (thinking someone is in love with you when they are not)
- best treatment: therapy + antipsychotics (50% of clients make full recovery - women better prognosis)
schizotypal personality disorder
similar eccentric behaviors like schizophrenia but more centered around personality.
- lifelong pattern of strange behavior that impacts work, social, interpersonal function
- maintain grasp of reality but behavior with very large suspicions of others and usually only have a few close friends and have odd perceptions of the world around them
- 0.6% Norwegian, 4.6% US and 0-1.9% clinical setting
- have similar but less severe problems with working memory, learning etc.
bio theories of Schizophrenia
1) genetic transmission (but cant fully explain disorder)
2) structural and functional abnormalities in specific areas of brain
3) history of birth complications or exposure to viruses
4) excess levels of dopamine (possibly serotonin, GABA, and glutamate)
genetic contributors to schizophrenia
- definite genetic factor but also have environmental risk factors at play as well
family studies
- as genetic similarity between family members with schizophrenia lowers their risk decreases
- first degree relative who shares 50% of genes with has a 10% change of developing, cousins = 3%
1% chance in general pop - increased risk for bipolar disorder
adoption studies
more likely to have diagnosis if biological parent had it
twin studies
heritability around 41-87%
- possible difference in rates across studies
- concordance in fraternal twin 14% and maternal 46%
- monozygotic twins that did not both have schizophrenia found differences in DNA for gene regulation of dopamine (epigenetic difference - possible environment events that changed utero brain development)
structural and functional brain abnormalities
- researchers look at it as a neurodevelopmental disorder of the brain during utero or early life
- Most often seen: reduction in grey matter in medial, temporal, superior temporal, and prefrontal cortexes
- if someone in family has, more odds of other members have smaller or less active prefrontal cortex (important for language, emotional expression, planning, etc)
prefrontal cortex differences
- this structure usually has major development between adolescence and young adulthood, which if starts dysfunction during this time makes since schizophrenia typically presents at this age
hippocampus
role: forming long-term memories
- see a difference when encoding information for storage or trying to retrieve information from memory
- differences in shape and volume of hippocamus
white patter
role: connection between ares of the brain, especially in areas of working memory
- can see changes in this structure before overt symptoms so it can be seen as early signs of the disorder
- impairs ares of the brain to work together
ventricles
- are fluid-filled spaces in the brain
- are enlarged which means other structures in the brain tissue have deteriorated
- will show social, emotional, and behavioral deficits before core symptoms of schizophrenia
- tend to have more severe symptoms and less responsive to meds
damage to developing brain - what causes neuroanatomical abnormalities in schizophrenia
- genetic and epigenetic factors together: birth complications, TBI, viral infections, nutritional deficiencies, and cognitive stimulation deficiencies
- birthing complications: emergency C-section, bleeding during pregnancy, preeclampsia, gestational diabetes, low birth rate
birthing complications
- inadequate oxygen to fetus before, during, or after delivery causing damage to neuroanatomy and contributes to lower grey matter and enlargement in lateral ventricular zone
- rodent studies found lower oxygen is associated with decreased myelination, tissue volume, and increased ventricles
- first “hit” of prenatal complication that disrupts brain development establishes a increased vulnerability to a second “hit” that occurs later in life and onset of psychiatric symptoms occur
Maternal Illness and Prenantal Exposure
higher rates if mother was exposed to flu, rubella, toxoplasmosis, and herpes during pregnancy and delivery
- localized bacterial infection increased psychotic disorder risk 1.6x and if system wide increased 3x
- more associated with development of disorder in males than female offspring
- flu season and babies impact are born around spring which if mother contracted flu would be during vital growth periods for fetus (fall & winter)
maternal immune response
MIA linked with autism and schizophrenia in offspring
- CRP is biomarker of inflammation and found at higher rates in mothers fighting an infection
- possible anti-inflammatory diet to pregnant women may reduce risk of offspring disorders
- possible impact to fetal serotonin production
gut microbiome
lots of research starting on this topic
neurotransmitters
the main neurotransmitters of this disorder is thought to be excess dopamine in prefrontal cortex and limbic system
- how think of role of HPA axis that can be triggered by stress and all contribute to dopamine release
meds and their impact on neurotransmitters
phenothiazines and neuroleptics both block the re-uptake of dopamine
- substances like amphetamines will increase the amount of dopamine and increase positive symptoms
- these drugs seem to help positive symptoms but not negative symptoms so shows not just dopamine is at play
revised dopamine theory
- thought that dopamine has different types of receptors and levels in areas of the brain
1. mesolimbic pathway: subcortical pathway and when abnormally functioning attributes to individuals finding importants in insignificant stimuli