PCOL 11-1 Schizophrenia (Antipsychotics)

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Questions and Answers

Which symptom is NOT listed as a negative symptom of schizophrenia?

Alogia (reduced fluidity of speech and thought)

Elevated mood swings (correct)

Flattened affect

Avolition/apathy

How long should signs persist for a diagnosis of schizophrenia?

3 months

1 month

6 months (correct)

1 year

What is required for a diagnosis of schizophrenia?

Presence of 2+ symptoms for at least a week

Social/occupational dysfunction (correct)

Ruling out schizoaffective disorder only

Signs persisting for > 3 months

What is the historical treatment for psychosis before the use of antipsychotics?

Frontal lobotomies and electro-convulsive therapy Signup and view all the answers

What is the primary mechanism of action for all antipsychotics?

D2 receptor antagonism Signup and view all the answers

At what percentage of D2 receptor occupancy do typical antipsychotics achieve clinical efficacy?

60 – 80 % Signup and view all the answers

Which of the following is a supported argument against the dopamine hypothesis of schizophrenia?

Antipsychotics upregulate DA receptors Signup and view all the answers

What is the primary function of the nigrostriatal dopamine pathway?

Movement regulation Signup and view all the answers

Which neurotransmitter deficiency is implicated in causing dopamine dysregulation in the NAc and medial PFC?

Glutamate Signup and view all the answers

What is the major abnormality related to dopamine in untreated patients with schizophrenia?

Elevated baseline of DA release Signup and view all the answers

Which brain area is primarily associated with the Tuberoinfundibular dopamine pathway?

Pituitary gland Signup and view all the answers

Which class of antipsychotics generally do not cause movement impairment?

Diazepines Signup and view all the answers

What is the primary molecular action of typical antipsychotics?

80% receptor occupancy at therapeutic doses Signup and view all the answers

Which atypical antipsychotic has a partial agonist action?

Aripiprazole Signup and view all the answers

Which two atypical antipsychotics have high affinity for D4 receptors?

Clozapine and risperidone Signup and view all the answers

Which side effect is specifically associated with Clozapine?

Agranulocytosis Signup and view all the answers

What is the long-term effect of upregulation of presynaptic D2 receptors?

Reduces dopamine release Signup and view all the answers

What is the first-line treatment for schizophrenia?

Atypical antipsychotics Signup and view all the answers

Which symptoms may take 6 – 12 months to improve with antipsychotic treatment?

Negative and cognitive symptoms Signup and view all the answers

What is the major side effect of typical antipsychotics related to metabolic syndrome?

Endocrine issues Signup and view all the answers

Study Notes

Symptoms and Diagnosis of Schizophrenia

Negative symptoms of schizophrenia can include lack of motivation, social withdrawal, and flat affect. A specific symptom not listed as negative must be identified.
Signs of schizophrenia should persist for at least six months for a proper diagnosis.
Diagnosis requires a combination of clinical assessment, documentation of symptoms, and evaluation of significant functional impairment.

Historical and Pharmacological Treatment

Prior to antipsychotics, treatments for psychosis included electroconvulsive therapy (ECT) and institutionalization.
The primary mechanism of action for all antipsychotics revolves around antagonism of dopamine D2 receptors.

Clinical Efficacy and Dopamine Hypothesis

Typical antipsychotics achieve clinical efficacy with approximately 65-80% D2 receptor occupancy.
Arguments against the dopamine hypothesis of schizophrenia include the observation of symptom improvement in some patients with low dopamine activity.

Dopamine Pathways and Neurotransmitter Interactions

The nigrostriatal dopamine pathway primarily regulates voluntary movement and motor control.
A deficiency in glutamate is implicated in causing dopamine dysregulation in the nucleus accumbens (NAc) and medial prefrontal cortex (PFC).
Untreated patients with schizophrenia often exhibit a major abnormality characterized by elevated dopamine levels.

Specific Pathways and Antipsychotic Classes

The Tuberoinfundibular dopamine pathway is primarily associated with regulating prolactin secretion from the pituitary gland.
Atypical antipsychotics generally do not cause significant movement impairments compared to typical antipsychotics.
The primary molecular action of typical antipsychotics includes antagonism of D2 receptors.

Atypical Antipsychotics and Side Effects

Aripiprazole is an atypical antipsychotic known for its partial agonist action at D2 receptors.
Clozapine and Quetiapine are atypical antipsychotics with high affinity for D4 receptors.
A specific side effect of Clozapine is agranulocytosis, a potentially severe reduction in white blood cells.

Long-term Effects and Treatment Guidelines

Long-term upregulation of presynaptic D2 receptors can lead to worsening of symptoms or increased sensitivity to dopamine.
First-line treatment for schizophrenia typically consists of atypical antipsychotics.
Negative symptoms may take 6 to 12 months to show improvement with antipsychotic treatment.
Metabolic syndrome is a major side effect of typical antipsychotics, posing risks like weight gain, diabetes, and cardiovascular issues.

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Description

Test your knowledge of schizophrenia with this quiz. Explore the multifactorial causes, risk factors, and the role of genetics and environment in the development of this cognitive function disorder.