PSYC1011 Lecture Notes - Lecture 32: Auditory Cortex, Weight Gain, Dopamine Hypothesis Of Schizophrenia
Schizophrenia
Schizophrenia is not multiple personality disorder
• Multiple personality disorder
o Dissociative identity disorder
o Presence of two or more distinct personality states
â–Ş Rare, controversial diagnosis
Schizophrenia
• Severe mental illness affecting approx. 1 in every 100 people
o 0.7% of population
• Prevalence
o Similar across different cultures
o Equal gender distribution
â–Ş More severe in men
• Age-of-onset - 18-30 years
o Occurs earlier in men
• Typically lifelong condition
• Costs
o Causes enormous suffering
â–Ş Suicide rate >10x the general population
o Financial cost
â–Ş Hospitals, community mental health, lost productivity, prisons
o Approx. 10% of homeless people have schizophrenia
• Symptoms
o Associated with profound changes in perception, cognition and emotion
â–Ş Affect their perception of the world
o Divided into:
â–Ş Positive symptoms
• Abnormal by their presence
• E.g. hallucinations
â–Ş Negative symptoms
• Abnormal by their absence
• E.g. flat emotional response, loss of interest
o Three factor model
â–Ş Reality distortion (psychotic symptoms)
â–Ş Disorganisation
â–Ş Negative symptoms
o Psychotic symptoms
â–Ş Hallucinations
• Hallucinations are abnormal perceptions
• Hearing things, seeing things, smelling things that other people cant
• Auditory hallucinations are most common
• Auditory verbal hallucination
• Present in ~70% of SZ patients
• AVHs are typically critical or abusive
• Often more than one voice
• Comments on their actions
• Visual, tactile, olfactory hallucinations can also occur
â–Ş Delusions
• Abnormal beliefs
• Very common in SZ (80%)
find more resources at oneclass.com
find more resources at oneclass.com
• Paranoid delusions
• Person believes that others are trying to harm them
• Delusions of control
• Person believes their body is being controlled by an external agent
• Delusions of reference
• Words of actions of strangers have special relevance to them
• Strangers trying to send them coded messages
o Disorganisation
â–Ş Refers to disconnected or incomprehensible thought and speech, bizarre behaviour
â–Ş Formal thought disorder
• Loose associations
• Tangential thinking
• 'word salad' - unable to understand what they're saying. Completely
incomprehensible
â–Ş Inappropriate affect
â–Ş Bizarre dress
o Negative symptoms
â–Ş Deficits in normal behaviour and cognition
• Flat affect
• Alogia (poverty of speech)
• Avolition (poverty of will)
• Cognitive deterioration
â–Ş Somewhat similar to the symptoms of Major Depressive Disorder
• Cognitive decline
• Psychotic symptoms - characteristic of schizophrenia (rare for other disorders)
o James Tilly Matthew
â–Ş First documents case of 'paranoid'
â–Ş Delusions of thought insertion
• First-Rank Symptoms
o (Kurt Schneider) - most characteristic symptoms of schizophrenia
â–Ş Audible thoughts (thought echo)
â–Ş Voices heard arguing
â–Ş Voices commenting on one's actions
â–Ş Delusions of control
â–Ş Thought withdrawal, insertion, broadcast
â–Ş Delusions of reference
o Diagnostic of schizophrenia according to some criteria
o Not unique to SZ but are more common in SZ compared to other psychotic disorders
o Delusions of control
â–Ş Patients believe that their actions are being controlled by an external force
o Delusions of thought insertion
â–Ş Patient believes that thoughts are being inserted into their mind by someone else
o Third-person auditory hallucinations
â–Ş Two or more voices talking about the patient or commenting on their actions
• What do these symptoms have in common?
o All reflect confusion between self-generated and externally-generated thoughts and actions
• How do we normally distinguish between self-generated and externally-generated events?
â–Ş Corollary discharges
• Are neural copies of motor signals
• Often sent to predict and suppress the response of sensory neurons to self-
generated actions
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Schizophrenia is not multiple personality disorder: multiple personality disorder, dissociative identity disorder, presence of two or more distinct personality states, rare, controversial diagnosis. 1 in every 100 people: 0. 7% of population, prevalence, similar across different cultures, equal gender distribution, more severe in men, age-of-onset - 18-30 years, occurs earlier in men, typically lifelong condition, costs, causes enormous suffering. Suicide rate >10x the general population: financial cost, hospitals, community mental health, lost productivity, prisons, approx. Strangers trying to send them coded messages: refers to disconnected or incomprehensible thought and speech, bizarre behaviour, formal thought disorder. "word salad" - unable to understand what they"re saying. Completely incomprehensible: inappropriate affect, bizarre dress, negative symptoms, deficits in normal behaviour and cognition. Flat affect: alogia (poverty of speech, avolition (poverty of will, cognitive deterioration, somewhat similar to the symptoms of major depressive disorder, cognitive decline, psychotic symptoms - characteristic of schizophrenia (rare for other disorders) First documents case of "paranoid: delusions of thought insertion.
