schizophrenia Flashcards
what is schizophrenia
characterized by disordered thinking in which ideas are not logically related, faulty perception and attention, a lack of emotional expressiveness & disturbances in behaviours
DSM-5 criteria for schizophrenia
symptoms last at least 6 months + at least 1 month of active-phase/acute symptoms (1-3)
1. delusions
2. hallucinations
3. disorganized speech
4. disorganized (or catatonic) behavior
5. negative symptoms (diminished motivation or emotional expression)
functioning in work, relationships, or self-care has declined since onset
comorbidity of schizophrenia
substance use, suicide (12x more likely)
more likely to die from any cause than people in the general population
prevalence, gender & age of schizophrenia
lifetime prevalence: 1%
affects men slightly more often than women - men have slightly more severe symptoms
age: usually late adolescence or early adulthood (earlier in men)
- have several acute episodes of symptoms + less severe but still debilitating symptoms between episodes
positive symptoms (schizophrenia)
comprise excesses and distortions, and include hallucinations and delusions
delusions = beliefs contrary to reality and frimly held despite disconfirming evidence - several forms (5 types)
hallucinations = sensory experiences in the absences of any relevant stimulation from the environment - often more auditory than visual
6 types of delusions
- thought insertion = believing thoughts that are not your own have been placed in your mind by an external source
- thought broadcasting = believing your thoughts are broadcast or transmitted, so that others know what they are thinking
- external force = believing that an external force controls your feelings or behaviors
- grandiose delusions = an exaggerated sense of own importance, power, knowledge or identity
- ideas of reference = reading personal significance into the trivial activities of others – e.g. think that overheard segments of conversations are about them
- paranoia/persecutory: thinking they are being targeted or are in danger (most common)
hallucinations in schizophrenia
- hear their own thoughts spoken by another voice
- hear voices arguing or hear voices commenting on behaviour
- ppl who have auditory hallucinations – may misattribute their own voice as being someone else’s voice
greater activity in Broca’s & Wernicke’s area when ppl w SC report hearing voices = problem in connections between speech production & speech comprehension areas
negative symptoms of schizophrenia
consist of behavioural deficits in motivation, pleasure, social closeness and emotion expression
avolition
asociality
anhedonia
blunted effect
alogia
what is avolition (apathy)
lack of motivation & absence of interest or inability to do usually routine activites, including work or school, hobbies or social activities
what is asociality
severe impairments in social interactions
- may have few friends, poor social skills, and very little interest in being with other people
- when around others – may interact only superficially + appear aloof or indifferent to the interaction
what is anhedonia
a loss of interest in or a reported lessening of the experience of pleasure
consummatory pleasure: the amount of pleasure experienced in the moment or in the presence of something pleasurable
anticipatory pleasure: the amount of expected or anticipated pleasure from future events or activities
ppl w SC - appear to have a deficit in anticipatory pleasure but not consummatory pleasure
what is the blunted effect
a lack of outward expression of emotion – may stare vacantly, the muscles of the face motionless, the eyes lifeless
- refers only to the outward expression of emotion, not to the inner experience, which is not diminished at all
- ppl w SC report experiencing the same amount or even more emotion than people w/o
what is alogia
a significant reduction in the amount of speech
- may answer a question with 1 or 2 words + not likely to elaborate on an answer with additional detail
disorganized symptoms of schizophrenia
disorganized speech: problems in organising ideas in speaking so that a listener can understand
disorganized behavior: may go into inexplicable bouts of agitation, dress in unusual clothes, act in a silly manner, hoard food or collect garbage
- catatonia
family studies of causes of schizophrenia
relatives of ppl w SC – increased risk + risk increases as the genetic relationship becomes closer
- neg symptoms may have a stronger genetic component than other symptoms
- study - incidence of SC was highest for children who had two parents admitted for SC
show that genes likely play a role in SC, but relatives also share common experiences = influence of env cannot be disregarded in explaining the higher risks among relatives
what are the 2 stages in schizophrenia
predormal – deterioration in normal functioning, mainly pos symptoms
residual – pos & disorganized symptoms leave, neg symptoms stay
twin studies of schizophrenia
risk for MZ twins (44%) is greater than DZ twins (12%) - but still less than 100% = not solely genetic factors (env factors)
adoption studies of schizophrenia
found that adoptees whose birth mother had it were way more likely to be diagnosed even when adoptive mother didn’t
no adoptees whose birth mother didn’t have it were diagnosed
molecular genetics in schizophrenia
DRD2 gene: encodes a specific type of dopamine receptor called D2 - implicated in the treatment of SC
COMT gene: associated w cog control processes that rely on prefrontal cortex – ppl w SC have deficits in this
- is on chromo 22 where rare mutations associated with SC have been identified
CNV mutations: 3x more common in SC but also related to other disorder (e.g. autism)
dopamine theory in schizophrenia
ppl w SC have excessive dop activity - mainly associated w pos & dis symptoms
support: effective drugs reduce dop activity, amphetamines (amplify dop activity) produce SC symptoms in ppl w/o it & make them worse in ppl who do
criticism: even when dop receptors are blocked it can still take time for symptoms to decrease + theory is too simple to explain whole
serotonin in schizophrenia
newer drugs partially block D2 receptors, but also block the ST receptor 5HT2
ST neurons regulate dop neurons in the mesolimbic pathway = involved in schizophrenia
GABA in schizophrenia
dop neurons regulate activity of other neural systems such as GABA neurons in prefrontal cortex
= GABA transmission is disrupted in the prefrontal cortex of people with SC
glutamate in schizophrenia
low levels of glutamate have been found in the CSF fluid of ppl w SC
+ low levels of enzymes needed to produce glutamate
elevated levels of homocysteine (amino acid) – interacts with the NMDA receptor (glutamate receptor) in ppl w SC
enlarged ventricles in schizophrenia
some ppl w SC have enlarged ventricles = implies loss of brain cells
related to poor performance on neurocog tests, poor functioning prior to onset & poor response to medication
prefrontal cortex in schizophrenia
associated with behaviors that are disrupted in SC (e.g. speech) - reductions in gray matter and overall volume = causes these deficits
- lower glucose metabolism
- less activation in the prefrontal cortex is related to more severe neg symptoms
loss of dendritic spines in schizophrenia
means that communication among neurons is disrupted = “disconnection syndrome”
- could be the cause of speech and behavioral disorganization seen in SC
temporal cortex in schizophrenia
ppl w SC have structural and functional abnormalities + a reduction in gray matter in temporal cortex + reduced vol in hippocampus, basal ganglia & limbic structures
HPA axis is disrupted in ppl w SC = stress reactivity & disrupted HPA axis are likely to contribute to the reductions in hippocampal volume
connectivity in the brain (schizo)
less connectivity in white matter in frontal & temporal cortices = associated w genetic predispodidtion for SC
less connectivity between brain networks correlated with poor performance on cog tests
env factors influencing brain development in schizo
- damage during gestation could cause brain abnormalities in SC – potentially cause reduced supply of oxygen to the brain = loss of cortical gray matter
- maternal infections during pregnancy = higher risk
- prefrontal cortex matures late = a problem in this area may not show in behavior until later
- develop of SC symptoms may be caused by loss of synapses bcuz of excessive pruning – may cause loss of necessary communication among neurons
poverty, urbanicity & migration in schizo
high rates of SC found in ppl with highest poverty levels – drift into poor neighborhoods as a consequence of the illness
likelihood of developing SC is (3x) higher for ppl living in urban areas compared to rural
risk for developing SC 3x higher in first-gen & 4x higher in second-gen migrants
family related factors in schizo
families of ppl w SC communicate more vaguely & have higher levels of conflict
bidirectional relationship found in high-EE families: critical comments by family members = more unusual though by relatives w SC, & unusual thoughts expressed by relative w SC = increased critical comments
first generation antipsychotics
dopamine antagonist – act on dop post synaptic neuron
- can reduce the pos & dis symptoms but have little or no effect on neg symptoms
- 30% don’t respond favorably to first-gen
- ppl who respond positively are kept on a maintenance dose of the drug
- many side effects
second generation antipsychotics
mechanism of action is not like the typical or first-gen antipsychotics – acts on a broader range of NTs + D4 receptors instead of D2
- equally as effective in reducing pos & dis
- no diffs in relapse or adverse side effects
- causes weight gain
common side effects of antipsychotics
sedation, dizziness, blurred vision, restlessness & sexual dysfunction
- extrapyramidal = resemble symptoms of Parkinson’s
- dystonia = a state of muscular rigidity
- dyskinesia = abnormal motion of voluntary and involuntary muscle
- akasthesia = an inability to remain still
- tardive dyskinesia = the mouth muscles involuntarily make sucking, lip-smacking, and chin-wagging motions
social skills training for schizo
designed to teach people w SC how to successfully manage a variety of interpersonal situations
- typically involves role-playing & other group exercises to practice skills, both in a therapy group & actual social situation
- achieve fewer relapses, better social functioning & higher quality of life
family therapy in schizo
a few different types have been designed – differ in length, setting & techniques but have several features in common (e.g. education & blame avoidance)
use various techniques to implement these strategies – e.g., identifying stressors that could trigger relapse & training families in communication skills
CBT in schizo
maladaptive beliefs of ppl w SC can benefit from CBT
- encouraged to test out delusional beliefs similar to ppl w/o SC
- help attach a non psychotic meaning to paranoid symptoms = reduce intensity & aversive nature
- can reduce neg symptoms
different types of catatonia
catatonic stupor = a state of psychomotor immobility in which one does not react to the env
rigidity = occurs when a person remains immobile
negativism = a person refuses to move in response to another person or an external stimulus
excitement = a person suddenly becomes tense for a reason that is invisible to the outside world (e.g a hallucination or delusion)
types disorganized speech in schizophrenia
loose associations/derailment = not being able to stick to one topic of convo
tangentially = unrelated, or strange answers to questions
neologisms = made up words that only makes sense to the person
clanging = person makes associations in their speech, based on the sound of words, rather than on the meaning of them
