Schizophrenia and other psychotic disorders
Transcript of Schizophrenia and other psychotic disorders
Schizophrenia and other psychotic disorders
Schizophrenia
Schizophreniform Disorder
Schizoaffective Disorder
Delusional Disorder
Schizophrenia
Different from other disorders in that there is no essential feature.
Variety due to historical development of the diagnosis
Benedict Morel (1852): démence précoce Emil Kraepelin: Deteriorating course of
dementia praecox (1898)– Kraepelin grouped together dementia paranoides,
catatonia, and hebephrenia.
Eugen Bleuler: Disturbances in process of the schizophrenias,1908
, schism or split, + , mind. Bleuler emphasized the breaking of
associative threads, lack of purposeful direction, and distractibility
Observed that there was not always early onset or deteriorating course
More history of diagnosis
Kurt Schneider: Pathognomic symptoms– Emphasized the importance of
hallucinations and delusions in diagnosis Adolf Meyer (1917) and the American
experience– A more flexible approach with subtypes– Emphasized the process-reactive
dimension
A history of overdiagnosis
Hoch (1949, 1955) added pseudoneurotic schizophrenia and pseudopsychopathic schizophrenia.
Schizophrenia became a catch-all diagnosis, much more commonly diagnosed in the United States than in Great Britain.
DSM-III (1980) began to narrow the diagnostic criteria
DSM-IV diagnostic criteria
A screening test– http://www.schizophrenia.com/sztest/survey2.php
At least two characteristic symptoms:– +Delusions *– +Hallucinations *
* Only one symptom required if it is bizarre delusions or continually commenting or conversing auditory hallucinations
– +Disorganized speech– +Grossly disorganized or catatonic behavior– Negative symptoms
More diagnostic criteria
Significantly long-lasting marked impairment of social or occupational functioning or self-care.
Lasts for six continuous months, including at least one month of active phase symptoms
No major depressive, manic, or mixed mood episodes
The syndrome duration
Total duration must be at least 6 months
ProdromeProdrome Active PhaseActive Phase Residual PhaseResidual Phase
ProdromeProdrome Active PhaseActive Phase Residual PhaseResidual Phase
Pro-drome
Pro-drome Active PhaseActive Phase Residual PhaseResidual Phase
The active phase must last at least 1 month
Subtypes of schizophrenia
Five types: Paranoid, disorganized, catatonic, undifferentiated, residual
Paranoid type– Preoccupied with one or more delusions,
or– Frequent auditory hallucinations– Speech, behavior, and affect are not
prominently impaired
Disorganized type (formerly hebephrenic) Behavior and speech are disorganized
– Clang associations and neologisms– Complete neglect of appearance
Flat or rapidly changing inappropriate emotion
Not paranoid type
Catatonic type At least two of
– Motor immobility• Catalepsy• Waxy flexibility• Stupor
– Purposeless excess movement– Extreme negativism: Motiveless resistance,
rigidity, mutism– Strange movements: posturing,
stereotyped movements, grimacing– Echolalia or echopraxia
Not paranoid or disorganized type
Two more types
Undifferentiated Residual
Critique of DSM-IV types
Low diagnostic reliability Little predictive validity Considerable overlap Possible improvements:
– Positive/negative/mixed symptom types– Positive/negative/disorganized symptoms– It is easier to distinguish between types of
symptoms than types of patients.
Etiologies of schizophrenia
The etiology may be complex, due to– Broad set of symptoms– Positive and negative symptoms
Genetic factors in etiology– 1% of general population– 10% in first-degree relatives of probands– 45% in identical twins of probands– Same rate in children of probands (16.8%) as
in children of their non-schizophrenic identical twins (17.4%) (Gottesman and Bertelsen, 1989)
Etiological factors
Inherited susceptibility or several genes are involved
Retrospective strangeness in childhood behavior
A stress trigger is implicated.
What are the genes?
Dopamine hyperactivity is found in schizophrenia, but the genes for the five types of DA receptors found so far are not linked to schizophrenia (Coon et al., 1993)
However, Akil et al. (2003) found a link to the COMT genotype.– The COMT gene is polymorphic: met-met, val-met, and val-
val.– The val-val variant is associated with poor prefrontal
functioning.– The prefrontal cortex DA system normally inhibits the corpus
striatum DA.– Uninhibited, striatal DA produces the positive symptoms of
schizophrenia.
The Genain Quadruplets (Rosenthal, 1963) (Genain means dire birth)
Hester, Nora, Myra, and Iris: NIMH
Environmental factors in etiology
We will see that dopamine hyperactivity relates to the positive symptoms of schizophrenia.
The negative symptoms may be due to brain damage: Some people with no family history of schizophrenia or any related disorder develop schizophrenia
Evidence of brain damage
Prenatal damage factors: Epidemiology Incidence of schizophrenia increases
with:– season of birth: late winter/early spring– viral epidemics in second trimester
(Tsuang, 2000)– population density and latitude– malnutrition or refeeding after thiamine
deficiency (cf. Korsakoff’s syndrome)– prenatal stress: WW II widows’ offspring
More on brain damage
Cellular migration errors Monochorionic monozygotic twins
– More likely to be mirror-image twins– Monochorionic concordance: 60%– Dichorionic MZ concordance: 10.7%– DZ dichorionic concordance: 10%
Concordant MZ twins have nearly identical fingerprints and palm prints; non-concordant MZ twins do not.
Evidence of brain damage in schizophrenia Neurological symptoms
– Catatonia and facial dyskinesias– Unusual rates of blinking, staring– Avoidance of eye contact– No blink reflex to a tap on the forehead– Stopped speech w/ looking away, esp. to right– Jerky eye movements and poor visual
tracking– Interdependence of eye and head
movements– Impaired reaction of pupils to light changes
More evidence of brain damage
Structural symptoms– Doubling of size of lateral ventricles– Abnormalities in temporal and frontal lobes and in
medial diencephalon– Smaller anterior hippocampus: smaller neurons– Decreased gray matter in left temporal lobe– Damage to left temporal lobe in adults may
produce schizophrenia de novo– Low activity in prefrontal cortex (hypofrontality)
And still more evidence…
Abnormal cell pruning after puberty (Keshevan, Anderson & Pettegrew, 1994)– Excessive pruning in the prefrontal cortex (negative
symptoms)– Failure of pruning in some subcortical structures
(positive symptoms) Higher incidence of schizophrenia in people
who experienced birth complications: – Oxygen deprivation, drugs, infections, endocrine
disorders
Variant dopamine hypothesis
Hypofrontality lowers sustained release of DA in nucleus accumbens
Nucleus accumbens DA receptors become hypersensitive
Normal DA activity from VTA triggers positive symptoms of schizophrenia
Drugs which treat schizophrenia lower DA activity; increase Parkinsonism
D2 receptors are supersensitive in 70% of people with schizophrenia (Grandy, 2005)
Evaluation of the dopamine hypothesis Why is the antischizophrenic effect of
drugs delayed? Why do DA levels have to be reduced
below normal to treat schizophrenia? Some newer antischizophrenia drugs
affect serotonin and GABA More neurochemicals are probably
involved in such a complex disorder
Other etiologies
Family causation Psychoanalysis Sociological theories
– Labelling– Social degradation/social drift– Double bind hypothesis
R.D. Laing
Schizophreniform Disorder
Same symptoms as Schizophrenia, but lasts from 1 to 6 months
No decline in functioning is required for this diagnosis
If the symptoms last less than one month but more than one day, diagnose Brief Psychotic Disorder
Schizoaffective Disorder
A mood episode coincides with the active phase of schizophrenia
Hallucinations or delusions occur for at least two weeks before or after the mood episode
The schizophrenias
1 2 3 4 5 6 >6Months duration of symptoms
BriefPsychotic Disorder
BriefPsychotic Disorder
Schizophreniform Disorder Schizo-phrenia
Delusional Disorder
Non-bizarre delusions for at least one month
None of the other symptoms of schizophrenia
Behavior not directly affected by the delusions is normal
Subtypes of Delusional Disorder
Erotomanic Grandiose Jealous Persecutory Somatic Mixed
Shared Psychotic Disorder
An otherwise unaffected person shares the delusional beliefs of a person with a psychotic disorder
Usually found only in long-term relationships of dominant-passive partners
Social isolation seems to be a necessary feature
A variant dopamine hypothesis
Brain structures in schizophrenia
Nucleus accumbens(VTA)
Substantia nigra
Neurodevelopmental model (Weinberger, 1995)
Prefrontal
Cortex
Ventral Tegmental Area
Basal ganglia(Limbic system)Mesocortical
pathway
Mesolimbicpathway
Disorganized speech
aka Formal thought disorder Incoherence Loose associations Derailment/distractibility Perseveration
Disorganized speech 1
“Takes less place. Cat didn’t know what Mouse did and Mouse didn’t know what Cat did Cat represented more on the suspicious side than the mouse. Dumbo was a good guy. He saw what the cat did, put himself with the cat so people wouldn’t look at them as comedians. Cat and Dumbo are one and alike, but Cat didn’t know what Dumbo did and neither did the mouse.”
Disorganized speech 2
“Everyone should have a good laugh. Don’t cry over it. Don’t tell anyone -- they will tell someone. Appreciate it without criticism. A word like milk shouldn’t be mentioned.”
Disorganized speech 3
“So to beseech you as full as for it. Exactly or as kings. Shutters shut and open so do queens. Shutters shut and shutters and so shutters shut and shutters and so and so shutters and so shutters shut and so shutters shut and shutters and. So and so shutters shut and so and also. And also and so and so and also.”
Disorganized speech credits
Disorganized speech 1 and 2 are from a person with schizophrenia, quoted in Zimbardo’s Instructor’s manual for Psychology and Life.
Disorganized speech 3 is from a poem by Gertrude Stein.
Grossly disorganized or catatonic symptoms “Other symptoms” (Davison & Neale)
– Inappropriate affect– Bizarre behavior
• Social blunders/residual rule-breaking• Treasuring trash
– Immobility – Waxy flexibility
Negative symptoms
Behavioral deficits:– Avolition– Alogia
• Poverty of speech• Poverty of speech content
– Anhedonia– Flattened affect
• Monotone; less facial expression of emotion
– Asociality
The brain with schizophrenia
MRI scans: The left brain
is normal, while the right brain is damaged.