Cognitive deficits in patients with schizophrenia

Question 1

Describe the profile of cognitive deficits in schizophrenia.

Answer 1

Global deficits from automatic sensory processing to higher cognitive functions, incl.
- sensory gating
- simple reaction time and processing speed
- attention
- verbal and visual learning and memory
- working memory
- executive functions
- social cognition
- intelligence

Question 2

Describe the progression of cognitive deficits from premorbid phases across the illness.

Answer 2

• ## The function decreases before the onset of psychosis (but around illness onset, before age 15): in the end of the premorbid phase –> predromal phase. After the onset of psychosis the function is at a plataeu (progressive phase) –> small increase with treatment

Question 3

Describe the relation between cognitive deficits and psychopathology.

Answer 3

• cognitive deficits are largely independent of clinical state
• independent from positive symptoms, some correlation between cognition and negative symptoms
• patients with comprehensive paranoid delusions generally have better cognitive functions

Question 4

Describe the relation between cognitive deficits and functional outcome.

Answer 4

High premorbid function + late onset of first episode –> predictors of good illness course

Question 5

Give examples of the heritability of cognitive functions and overlap with schizophrenia liability

Answer 5

• The regions, connections and functions of the brain develop and mature are staggered, overlapping stages
• parallel cognitive development and maturation

Question 6

Describe the neurodevelopment of schizophrenia - how are neuroplasticity affecting the patients?

Answer 6

Some stages of brain development are characterized by more plasticity –> increased sensitivity to impact of both endogenous and environmental factors

Question 7

Describe the neurodevelopmental hypothesis of schizophrenia.

Answer 7

Disturbed pruning process in gray matter and disturbed myelination of white matter –> extended period from birth until full ilness presentation

Question 8

Describe the correlation between cognition and diagnosis in schizophrenia.

Answer 8

• patients with results within the normal range have an estimated premorbid cognitive functional level 1 SD higher than healthy control with similar results
• 96 % patients have lower cognitive scores than expected based on maternal education

Question 9

Describe the severity of cognitive deficits in schizophrenia.

Answer 9

• most domains between 1-1,5 SD below the norm
• most common deficits: executive and attention
• largest effect sizes: processing speed, and for some verbal memory