For this exercise, I divide students up into small groups and ask them to make a differential diagnosis of "Mr. Smith." Because Mr. Smith's case is somewhat ambiguous, making the diagnosis is not straightforward. The exercise helps students appreciate various aspects of diagnosis, including how to assess symptoms, how to apply inclusion/exclusion criteria, the necessity of obtaining accurate information about the patient, and the sometimes unavoidable ambiguity of diagnostic categories.
Diagnosing Mr. Smith
Below is the handout for the exercise.
Mr. Smith, a sixty year old employee of a local taxation office, claims that the IRS has been "observing Him" for the past three weeks. He believes that some errors he accidentally made at his job have led the federal IRS to suspect him of gross tax fraud on his own income tax return. Even though his wife and boss have tried to convince him that his perceptions are inaccurate, he is convinced that IRS agents are watching his house, tapping his phone, and perhaps hiding in the attic. Because he fears the consequences of this "investigation," he often avoids going to work, and, when at home, draws all the curtains and removes the phone from its hook.
Diagnosing Mr. Smith
Mrs.Smith reports that her husband seems to have changed significantly since he lost his first job, which was approximately one year ago. Once being very active fixing up the house, Mr. Smith now spends most of his free time munching on food or dozing on the couch. Although he often stated that he enjoys his new job at the taxation office, he sometimes complains of "having trouble figuring out the numbers" - which surprises Mrs. Smith since he was always very good at mental calculations. Mr. Smith state that "all this stuff really doesn't bother me all that much," and strongly denied any suicidal thoughts when the psychologist asked him about this possibility. "I only came to see a shrink because my wife and two sons suggested it."
The objective: Using the criteria below, diagnose Mr. Smith
as either a paranoid disorder or a major depressive episode.
A. A persistent persecutory delusion is present (e.g., beliefs about being conspired against, cheated, spied upon, followed, poisoned or drugged, etc.)
Diagnostic Criteria for a Paranoid Disorder:
B. Emotion and behavior appropriate to the content of the delusional system
C. Duration of illness of at least one week
D. Symptoms of schizophrenia are not present (e.g., hallucinations, incoherence, bizarre delusions)
E. Cannot be diagnosed as a depressive or manic syndrome
F. Condition is not due to an organic or physiological cause
Note: These individuals rarely seek treatment and often are brought for care by relatives, associates, or government agencies. Eccentric behavior is common.
A. At least 4 of the following symptoms are present every day for a period of at least 2 weeks:
Diagnostic Criteria for a Major Depressive Episode:
1. poor appetite with weight loss, or increased appetite with weight gainB. None of the symptoms of schizophrenia are present (see above)
2. insomnia or hypersomnia
3. psychomotor agitation or retardation
4. loss of interest or pleasure in usual activities, or a decrease in sexual drive
5. loss of energy or fatigue
6. feelings of worthlessness, guilt, self-reproach
7. complaints or evidence of a decreased ability to concentrate (slow thinking, indecisiveness)
8. recurrent thoughts of death, wishes to be dead, suicide attempt
C. Not due to an organic or physiological cause
Note: If patient reports feeling "blue, sad, hopeless, low, down in the dumps," etc., use diagnosis Depressive episode with Melancholia.
Note: If gross impairment of reality testing is present (e.g., hallucinations, delusions) use diagnosis "Depressive episode with Psychotic Features"