psychopathology
Schizophrenia
Schizophrenia: Diagnosis
Symptoms
2 or more, present for a significant portion of
time, for a month unless treated
Delusions: paranoid most of the time
Hallucinations: auditory, visual, somatic, etc
Disorganized speech (derailment or
incoherence)
Grossly disorganized or catatonic behaviour
Negative symptoms: affective flattening, alogia,
avolition, anhedonia, attention (lack of)
If delusions are bizarre or hallucinations are
consistent on one voice making comments
about the person’s activities and having
conversations, only one symptom is necessary
Schizophrenia: Diagnosis
Social / occupational dysfunction
Persists for at least six months: Includes a month of
active symptoms and prodromal or negative
symptoms
Schizoaffective and mood disorder exclusion: no
mood disorder, or a very brief one has occurred
during the active phase
Substance abuse/general medical condition
exclusion
Relation to a pervasive developmental disorder
Course:
Episodic with interepisodic residual symptoms
Episodic with no interepisodic residual symptoms
Continuous
Single episode in partial remission
Single episode in full remission
Other unespecified pattern
Schizophrenia: Diagnosis
Types
Paranoid:
Prominent delusions and hallucinations
Non prominence of disorganized speech, disorganized or
catatonic behaviour, flat or inappropriate affect
Disorganized:
Prominent disorganized speech, disorganized behaviour, flat
or inappropriate affect
Not catatonic in nature
Catatonic:
Catalepsy or stupor
Excessive motor activity
Extreme negativism or mutism
Posturing, stereotyped movements, mannerisms, grimacing
Echolalia and echopraxia
Undifferentiated
Residual
Schizophrenia: Facts
1 % of the general population
affected
2-3 % have schizotypal personality
disorder
33 billion dollars in annual costs to the
US
30 % of the homeless are
schizophrenic
Schizophrenia: Anatomopathology
Early in the disease there is a reduction to
the left globus pallidus = no connection
between frontal lobes and basal ganglia
Frontal lobes do not respond to stimulation
with increased blood flow
Cortex in medial temporal lobe is thinner,
left anterior hippocampus is smaller
Lateral and third ventricles enlarged with
widening of sulci in temporal and frontal
lobes
Changes seen in prominent negative
symptoms
Schizophrenia: Causes
Genetic predisposition
Developmental injury of neurons in white matter
under layer VI or cortical subplate. Significantly
reduced in frontal and temporal cortex but
increased 3 mm underneath (abnormal migration)
Viral infections during pregnancy
Premature switch off of genes encoding for
migration?
Excessive dopaminergic transmission in the
mesolimbic system = positive symptoms
Decreased activity in the mesocortical connections
of prefrontal cortex = negative symptoms
Schizophrenia: causes
D2, D3 and D4 blockade
Increased sensitivity over time
Increased dopaminergic activity
Downregulation of 5HT2 receptors (stimulation
is hallucinogen)
PCP produces schizophrenia like symptoms
PCP binds dopaminergic and NMDA
glutamatergic receptors
PCP enhances dopamine release in the
mesolimbic pathway while it block
dopamine release in the mesocortical
system
Schizophrenia: Family studies
Definitely familiar
Risk for relatives: 2nd degree = 4%; 1st degree =
9%; DZ = 17%; MZ = 48%
Amongst 1st degree: 6% parents, 9% siblings and
13 % offspring if one parent is affected but 46% if
both are affected
Affected offspring have:
parents severely affected by the disease
unstable families with more hospitalizations
Perinatal complications
Attention problems in childhood
Personality disorders
Schizophrenia: Twin and adoption studies
TWIN STUDIES
Concordances for MZ between 41-65 and DZ 0-
28
Heritability is up to 80%
Discordance most probably environmental for
MZ
ADOPTION STUDIES
Risk does not decreased if reared apart by non-
affected parents
Findings support genetic familial studies
Shared or non shared environment seem to play
no major role in the development of the disease.