Summary Chapter 4 Stahls Psychopharmacology notes 5th ed

Chapter 4: Psychosis, Schizophrenia, and the Neurotransmitter Networks Dopamine, Serotonin
and Glutamate

Symptoms of Psychosis
 Delusions: fixed held beliefs that are often bizarre
o Positive symptom
o No rational basis and no amount of accurate information can sway the belief
 Hallucinations: perceptual experiences from any sensory modality
o Vivid and clear like normal perceptions
o NOT under voluntary control
o Positive symptom
 Negative Symptoms
o Diminished emotional expression and decreased motivation
 Types of Psychosis
o Perceptual Distortions
 Feeling that familiar people have changed or become different
 Being distressed by hallucinatory distortions
 Hearing voices blame and accuse
 Seeing visions, olfactory, tactile or gustatory hallucinations
o Motor Disturbances
 Peculiar movements or postures
 Overt signs of tension
 Odd giggles and grins
 Repetitive gestures, muttering to oneself
o Paranoid Psychosis
 Paranoid Projections
 Preoccupation with delusional belief that people are talking about them
 Feeling that one is being persecuted or conspired against
 Parkinson’s Psychosis
o Believing that one’s spouse is being unfaithful
o Believing one’s spouse is stealing money from them
 Hostile Belligerence
 Verbal expressions of feelings of hostility
 Expressing an attitude of disdain
 Manifesting a hostile, sullen or irritable attitude
 Blaming others for problems, experiencing feelings of resentment
 Expressing suspicion of people
o Especially seen in schizophrenia or drug induced psychosis
 Grandiose Expansiveness
 Exhibiting attitude of superiority
 Hearing voices that are praise or extol
 Believing that one has unusual powers or is a well-known personality
 Belief that one has a divine mission
o Commonly seen in schizophrenia and manic psychosis
o Disorganized/Excited Psychosis
 Conceptual Disorganization
 Giving answers that are irrelevant or incoherent
 Using neologisms (made up words)
 Repeating certain words or phrases

 Disorientation

,  Not knowing where one is, what season it is, what year it is
o Common with dementia and drug induced states
 Excitement
 Expressing feelings without restraint
 Pressured speech, loud and boisterous
 Dramatizing symptoms
 Elevated mood, attitude of superiority
o Especially characteristic of mania or schizophrenia
o Depressive Psychosis
 Psychomotor retardation and apathy
 Slowed speech, slowed facial expressions
 Deficiencies in recent memory
 Thought blocking
 Apathy towards oneself and one’s problems
 Anxious self-punishment and blame
 Tendency to blame or condemn oneself
 Apprehension regarding future events
 Worrying over many things
 Expressing feelings of guilt and remorse
 Preoccupation with suicidal thoughts, unwanted ideas and specific
fears
 Feeling wrong or sinful
o Often seen in psychotic depression

The Three Major Hypotheses of Psychosis and their




Neurotransmitter Networks

, The Classic Dopamine Hypothesis of Psychosis and Schizophrenia
The Dopamine Neurotransmitter Network
o DA is synthesized in dopaminergic nerve
terminals from the amino acid tyrosine
 Tyrosine pump takes tyrosine from
extracellular space into the neuron to
synthesize DA
 First rate limiting enzyme is
tyrosine hydroxylase (TOH)
 Second enzyme is DOPA
decarboxylase (DDC)
 DA is then taken up into synaptic
vesicles by VMAT2
 Excess DA that isn’t stored is
inactivated by MAO-A and MOA-B

o Presynaptic transporter (reuptake pump) DAT
 Takes it out of the synapse and re-stores
it back into the presynaptic nerve
terminal
 DATs in the striatum
 Secondary inactivation:
 Extracellularly
 Catechol-O-methyltransferase (COMT)
o Pre-frontal cortex
 DATs are sparse
 Mainly inactivated by COMT