Psychosis: How does it manifest and how is it diagnosed?

Question 1

What are delusions?

Answer 1

Beliefs demonstrably untrue, firmly and consistently held
despite disconfirming evidence or logic, which are out of
keeping with cultural norms

Question 2

What are hallucinations?

Answer 2

Sensory experiences in the absence of the appropriate
external stimulus (may or may not have insight into the unreal
nature of the perception)
◦ Any sense can be involved

Question 3

What types of delusions are there?

Answer 3

1. Persecutory
2. Reference
3. Grandiose
4. Nihilistic delusions
5. Delusions of control
6. Thought interference

Question 4

What are positive symptoms?

Answer 4

Presence of additional stimuli

Question 5

What negative symptoms are there?

Answer 5

1. Anhedonia (trouble in enjoying activities and no motivation)
2. Blunted affect
3. Catatonia

Question 6

What cognitive symptoms are there?

Answer 6

Aleman et al (1999) and Chan et al (2010)
1. Poor special memory
2. Poor episodic memory
3. Emotion recognition
4. Reaction time
5. Verbal recognition

Question 7

What are arguments for diagnosing people?

Answer 7

1. Makes treatment access faster
2. Helps with understanding what is happening to people–> Good for everyone else affected by the condition (not just the person)
3. People can be included in the RCTs (&other research)
4. Psychosis can present as a secondary condition so we want to know the primary one

Question 8

DSM 5 Criteria for Schizophrenia

Answer 8

A. Two (or more) of the following, each present for a significant
portion of time during a 1-month period (or less if successfully
treated):
(1) delusions; (2) hallucinations; (3) disorganized speech (e.g.,
frequent derailment or incoherence); (4) grossly disorganized or catatonic behavior; (5) negative symptoms, i.e., affective
flattening, alogia, or avolition

B. Social/occupational dysfunction

C. Disturbance persists for at least 6 months. This 6-month
period must include at least 1 month of symptoms (or less if
successfully treated) that meet Criterion A (i.e., active-phase
symptoms) and may include periods of prodromal or residual
symptoms

Question 9

What is dopamine hypothesis?

Answer 9

Howes & Kapur (2009) proposed the theory Aberrent salience (Kapur, 2003)

Support: Howes et al. (2011) PET study, longitudinal change in pre-synaptic striatal dopaminergic function within subjects as they progressed from a prodromal phase to the first episode of psychosis.

> Increase in striatal dopamine synthesis capacity as clients develop psychosis

Slifstein et al. (2015) Overactivity in mesolimbic dopamine pathway is thought to underlie positive symptoms + Underactivity of mesocortical dopamine pathway - negative and cognitive symptoms

+ Support also given by antipsychotics working on D2 receptor inhibition with decrease in positive symptoms = reducing dopamine decreases symptoms AND amphetamines make psychosis symptoms worse

Question 10

Glutamate Hypothesis

Answer 10

Blocking NMDA glutamate receptors with ketamine or PCP can
lead to psychotic symptoms (positive, negative and cognitive
symptoms)

Majority of genes associated with schizophrenia are linked to
glutamate

In schizophrenia there may be hypo-function of NMDA receptors on certain GABA interneurons -> increase pyramidal cell firing and dysregulation of dopamine