Introduction of schizophrenia
Classic definition: Schizophrenia is a severe, chronic mental disorder characterized by disturbances in thought, perception and behaviour. (DSM-5)
To describe the symptoms of schizophrenia
General 3 kinds of symptoms:
Positive Symptoms:
hallucinations (sensory perception, can be visual or auditory); Delusions (Beliefs that conflict with reality, can be persecutory, erotomanic, somatic, grandiose)
Negative Symptoms:
Ø Flat affect- restricted range of expressed emotions.
Ø Alogia - poverty of speech.
Ø Avolition - loss of motivation/an inability to initiate and persist in goal-directed activities.
Ø Anhedonia - lack of pleasure/interest in doing things.
Ø Social withdrawal.Cognitive Symptoms
To understand the general course of schizophrenia
Ø Approx. 20% of patients achieve a full recovery and 20% a ‘social’ recovery.
Ø Majority of patients experience multiple psychotic episodes.
Ø Cycles of relapsing and remitting.
Ø Subsequent episodes are often harder to recover from or recovery is less quick.
Ø Residual symptoms and functional decline.
Ø Term ‘chronic’ schizophrenia.
Ø Important to treat effectively and as early as possible!
Ø Duration of untreated psychosis (DUP) is a major predictor of outcome.
Ø Focus towards prevention strategies.
To detail some of the cognitive deficits that are characteristic of schizophrenia
General 7 types of deficits
- Verbal fluency: e.g., producing words from a category
- Attention/ vigilance: e.g., psychomotor vigilance task
- Visual learning/ memory: e.g., delayed match to sample task
- Verbal learning/ memory: e.g., auditory verbal learning task
- Social learning: e.g., reward learning task
- Working memory: e.g., n-back task
- Reasoning/ problem solving: e.g., tower of London task
Brain dysfunction in schizophrenia (neuroimaging methods and hypotheses)
To describe the key hypotheses of schizophrenia
There are a number of key hypotheses that aim to explain the causes of schizophrenia including dopamine, salience, glutamate, disconnection, neurodevelopmental (to name a few!). Each have their strengths and weaknesses.
Evidence:
Dopamine and reward learning
RPE (reward prediction error) signalling
MR spectroscopy
The dysconnectivity hypothesis
Neurodevelopmental hypothesis
Structural MRI
To describe the key hypotheses of schizophrenia
Schizophrenia is characterized by widespread brain dysfunction including structural, functional and alterations in neurotransmitter systems.
To detail some of the neuroimaging methods used to understand these brain dysfunctions
Neuroimaging modalities such as fMRI, MRI, MRS, PET can help us to understand these brain dysfunctions (and many more e.g., EEG, MEG…).
Heterogeneity problem (symptoms, classification, cognition, treatment response and new approaches to dealing with this).
To describe the problem of heterogeneity in schizophrenia.
Heterogeneity (large interindividual differences) is a large problem in schizophrenia research and has slowed progress towards new treatments and prevention strategies.
To understand treatment resistance as an example of heterogeneity in schizophrenia.
Antipsychotic treatment response in schizophrenia is an example of a form of heterogeneity that may be better understood as two subtypes of the disorder
To detail some of the new approaches to this problem.
New approaches that move away from the classic diagnostic criteria may aid in new developments and towards precision medicine
Autism
What is Autism?
Development of the diagnostic concept
1925 Grunya Efimovna Sukhareva, a Soviet child psychiatrist, published descriptions of ‘schizoid psychopathy’
1967 ICD-8 ‘Infantile autism’ under Schizophrenia DSM-I and II: ‘Childhood schizophrenia’
1978 ICD-9: ‘Autistic disorder’ a childhood psychosis
1980 DSM-III: ‘Infantile autism’ a ‘Pervasive Developmental Disorder’
1993 ICD-10: ‘Autistic disorder’
1994 DSM-IV: ‘Autistic disorder’, ‘Asperger disorder’, ‘PDD-NOS’
2013 DSM-5: ‘Autism Spectrum Disorder’
Is autism increasing?
Russell, G., et al., 2021. Child Psychology Psychiatry, 2021, DOI: (10.1111/jcpp.13505)
Levels of description: biological, behavioural, cognitive
Psychological
Autism is… highly heritable
Autism is… a differently wired brain
Autism is… a disorder of social communication
Autism is… a different way of processing the world
Cognitive
No single explanation at the Cognitive level
Current and future issues
Conclusions
Autistic people have always been with us; autism is not rare
The concept/diagnosis of ‘autism’ is relatively new and has evolved
Much research is underway into the biological causes; heterogeneity an obstacle
The diagnosis remains behavioural; is it serving older people and women well?
Autism is rarely ‘pure’; additional problems are good treatment targets
Neurotypicals need to increase empathy, acceptance, and respect for difference
