Schizophrenia

Question 1

How long do SCZ symptoms need to last for?

Answer 1

2 symptoms for 6 months.

Question 2

Positive Symptoms

Answer 2

• Delusions: beliefs not based on reality.
• Hallucinations (ex: auditory, tactile).
• Speech & behaviour disorganization.

Question 3

Negative Symptoms

Answer 3

• Flat affect: lack of expressed emotion.
• Avolition: lack off initiative & motivation.
• Alogia: reduced speech.
• Anhedonia.
• Social withdrawal.

Question 4

Cognitive Symptoms

Answer 4

Impaired working memory, executive functioning, & attention.

Question 5

how do amphetamines influence SCZ?

Answer 5

greater DA release in SCZ = exaggerates existing psychosis.

Question 6

DA Imbalance Hypothesis

Answer 6

Suggests that SCZ symptoms are due to reduced DA function in mesocortical neurons & excess DA function in mesolimbic neurons.

Question 7

Mesocortical Path

Answer 7

• Underactive DA.
• Involved with negative symptoms.
• Higher level cognitive deficits.

Question 8

Mesolimbic Path

Answer 8

• Overactive DA.

- Involved with positive symptoms, ex: abnormal salience to stimuli (thinking normal stimuli has some special meaning).

Question 9

Decreased glutamate signaling

Answer 9

• produce low DA release in PFC –> intensifying negative & cognitive symptoms.
• fails to inhibit mesolimbic firing –> leading to excess DA release in NACc & produces positive symptoms.

Question 10

PCP/Ketamine models

Answer 10

Blocking NMDA receptor with PCP/ketamine leads to increased DA mesolimbic release → mimics positive, negative SCZ symptoms, & cognitive deficits.

Question 11

Neuroleptics routes of administration

Answer 11

• Aka Antipsychotics.
• Daily oral administration.
• Injections once a month.

Question 12

Therapeutic efficacy

of Neuroleptics

Answer 12

• Most linked to blockade of D2 receptors.

- Higher concentration of D2 to bind = requires higher dose to be effective.

Question 13

1st generation antipsychotics examples

Answer 13

chlorpromazine &haloperidol.

Question 14

Side Effects of 1st Gen Antipsychotics

Answer 14

• Extrapyramidal symptoms
• Parkinsonian syndrome
• Tardive dyskinesia
• Hormone dysregulation
• Neuroleptic malignant syndrome

Question 15

Extrapyramidal symptoms

Answer 15

drug-induced movement disorders.

Question 16

Parkinsonian syndrome

Answer 16

symptoms resemble parkinson’s disease.

Question 17

Tardive dyskinesia

Answer 17

stereotyped involuntary movements, particularly of the face and jaw.

Question 18

Hormone dysregulation

Answer 18

Breast enlargement & tenderness, decreased sex drive, lack of menstruation, increase release of prolactin, inhibition of growth hormones.

Question 19

Neuroleptic malignant syndrome

Answer 19

Characterized by fever, rigidity, altered consciousness, & ANS instability (rapid heart rate& fluctuation in blood pressure).

Question 20

Neurotransmitters involved in Parkinsonian Symptoms

Answer 20

1. ) Degeneration of DA cells causes cholinergic neuron to fire less, causing the movement disorder.
2. ) Blocking DA receptors in striatum leads to cell degeneration.
3. ) ACHe inhibitors block receptors & reduce parkinson’s symptoms.

Question 21

Abuse potential of 1st Gen Drugs

Answer 21

• Little tolerance, takes weeks to build up.
• Lack of physical dependence (no withdrawal symptoms).
• High therapeutic index → overdose is rare.
• No reinforcement → effects are unpleasant.

Question 22

Atypical Antipsychotics

Answer 22

2nd generation.

• Include selective D2 receptors antagonists & broad-spectrum antipsychotics.
• Recent findings encourage use of older first-generation drugs = effective at lower cost.

Question 23

Selective D2 receptor antagonists

Answer 23

Bind to D2 receptors.

• Mild sedation.
• Hormonal side effects.

Question 24

Broad-Spectrum antipsychotics

Answer 24

Clozapine → high affinity for D4, 5-HT, NE, & ACh.

• Increases release of ACh & DA.
• Addresses positive, negative & cognitive effects.
• Can cause weight gain.

Question 25

Risks of Clozapine

Answer 25

agranulocytosis = serious blood abnormality.

Question 26

Risks of Risperidone

Answer 26

can cause severe elevations in blood sugar & insulin resistance = type 2 diabetes.

Question 27

Dopamine System Stabilizer

Answer 27

3rd generation.

• Ex: Aripiprazole.
• Partial D1 agonist.
• Reduces excesses DA → reduces positive symptoms.
• Enhances DA receptors → reduces negative symptoms.