Schizophrenia Spectrum and other Psychotic Disorders

Question 1

What condition is marked by a either a major depressive or manic episode concurrent with symptoms of schizophrenia?

Answer 1

Schizoaffective disorder

Question 2

A 32-year-old man is brought to the emergency department by his mother. She says that he has stayed up late every night for the past week, praying and shouting that he is “the Messiah.” The patient speaks rapidly without interruption and believes that he has special powers to end all wars and save humankind. He shakes his head in response to voices, saying that there is a fight between good and evil and that he must “drown out the devil.” The patient has had a history of psychiatric illness since his early 20s, when he was discharged from the military due to severe depression and suicidal ideation. At that time, he heard voices blaming him for all the suffering in war. He has been hospitalized for several depressive episodes over the past 10 years. Between hospitalizations, he has had periods lasting for several months during which his mood is stable, but he has continued to hear the voices of God and the devil. The patient lives with his mother and is able to work stocking groceries, but he spends most of his time at home alone. He has been prescribed risperidone, but his mother is unsure if he takes it regularly. Which of the following is the most likely diagnosis?

Answer 2

This patient’s clinical presentation and history are consistent with a diagnosis of schizoaffective disorder, bipolar type. He currently exhibits symptoms of a manic episode (decreased need for sleep; grandiose delusions; loud, pressured speech). He also meets DSM-5 criterion A for schizophrenia ( ≥ 2 of the following: delusions, hallucinations, disorganized speech, grossly disorganized behavior, negative symptoms). His history indicates periods of persistent hallucinations for ≥ 2 weeks in the absence of a major depressive or manic episode (ie, when his mood is stable).

Schizoaffective disorder can be differentiated from schizophrenia and bipolar disorder by assessing the relationship of mood and psychotic symptoms over the course of the illness. If mood symptoms occur in schizophrenia, they are typically present for a small portion of the illness. In contrast, this patient’s mood symptoms appear to be present for a significant portion of his illness, making schizophrenia less likely. In bipolar I disorder, psychotic symptoms occur exclusively during manic or depressiv`e episodes. The persistence of hallucinations when this patient’s mood is stable rules out a bipolar I diagnosis.

Question 3

What are the effects of D2 blockade with use of antipsychotics?

Answer 3

Reduces positive symptoms

Worsens negative symptoms

Tremors, dystonia, rigidity

Galactorrhea, amenorrhea

Question 4

What symptoms of schizophrenia are classified as “positive symptoms”?

Answer 4

Hallucinations (especially auditory)

Delusions (fixed, false beliefs)

Disorganized speech (word salad, incoherence)

Disorganized behavior (bizarre or purposeless activity)

Question 5

What symptoms of schizophrenia are classified as “negative symptoms”?

Answer 5

Flat or blunted affect (reduced emotional expression)

Alogia (poverty of speech)

Avolition (lack of motivation)

Anhedonia (inability to feel pleasure)

Asociality (social withdrawal)

Question 6

Which dopamine pathway is responsible for positive symptoms of schizophrenia?

Answer 6

The mesolimbic pathway. Positive symptoms arise from overactivity of dopamine in this pathway.

Question 7

Which dopamine pathway is responsible for negative symptoms of schizophrenia?

Answer 7

The mesocortical pathway. Negative symptoms arise from reduced dopamine activity in this pathway.

Question 8

Which symptoms of schizophrenia are worsened by D2 blockade in the mesocortical pathway?

Answer 8

Negative symptoms: Flat affect, alogia, avolition, anhedonia, asociality

Cognitive dysfunction: Impaired executive function, working memory, and decision-making

Question 9

What is the difference between first-generation and second-generation antipsychotics?

Answer 9

First-generation antipsychotics (FGA): Block D2 receptors, more effective for positive symptoms, may worsen negative symptoms.

Second-generation antipsychotics (SGA): Block D2 and 5-HT2A receptors, effective for both positive and negative symptoms.

Question 10

How does D2 blockade in the nigrostriatal pathway cause extrapyramidal symptoms (EPS)?

Answer 10

The nigrostriatal pathway controls movement. D2 blockade disrupts the balance of dopamine and acetylcholine, leading to:

Dystonia (muscle spasms)
Parkinsonism (rigidity, bradykinesia)
Akathisia (restlessness)
Tardive dyskinesia (long-term movement disorder)

Question 11

How does D2 blockade in the tuberoinfundibular pathway cause hyperprolactinemia?

Answer 11

Dopamine normally inhibits prolactin release from the anterior pituitary. D2 blockade increases prolactin, leading to:

Galactorrhea (milk production)
Gynecomastia (male breast enlargement)
Amenorrhea (absence of menstruation)

Question 12

What is the most appropriate initial treatment for positive symptoms of schizophrenia?

Answer 12

First-line treatment: Second-generation antipsychotics (SGA) like risperidone, aripiprazole, or olanzapine.

First-generation antipsychotics (FGA) like haloperidol are effective but have a higher risk of EPS and negative symptom worsening.