Chapter 1 Differential Diagnoses

Question 1

What are the steps of differential diagnoses

Answer 1

1. Rule out malingering and factitious disorder
2. Rule out substance etiology
3. Rule out a disorder due to a general medical condition
4. Determine the specific primary disorder
5. Differentiate adjustment disorders from the residual Other Specified or Unspecified Disorders
6. Establish the boundary with no mental disorder

Question 2

What is the difference between Malingering and Factitious Disorder

Answer 2

Malingering is when the motivation is the achievement of a clearly recognizable goal (eg. Insurance compensation/obtaining drugs/etc), Factitious is when deceptive behavior is present even in the absence of obvious external rewards

Question 3

In which 5 situations should suspicions be raised for a malingering or Factitious disorder

Answer 3

1. Clear external incentives to diagnosis
2. When symptoms conform more to lay perception of mental illness than to recognized clinical entity
3. When nature of symptoms shifts radically from one clinical encounter to another
4. When the patient has a presentation that mimics that of a role model
5. When the patient is characteristically manipulative/suggestible

Question 4

What are the 3 important steps in ruling out substance etiology

Answer 4

• determine whether person has been using a substance; history taking/physical examination, consult family members and obtain laboratory analysis of body fluids
• once established, determine whether there is an etiology between it and the psychiatric symptomatology
• after deciding that a representation is due to direct effects of a substance/medication, you must then determine which DSM-5 Substance-Induced Disorder best described the presentation

Question 5

What are the 3 possible relationships between the substance etiology and the psychiatric symptomatology

Answer 5

1) psychiatric symptoms result from the direct effects of the substance on the CNS
2) substance use can be the consequence or an associated feature (rather than a cause) of psychiatric symptomatology
3) both the psychiatric disorder and the substance use can be initially unrelated and relatively independent of each other

Question 6

What are 4 reasons the differential diagnoses of a Disorder Due to a General Medical Condition is difficult

Answer 6

1. Symptoms of psychiatric disorders and many medical conditions can be identical
2. Sometimes the first presenting symptoms of a general medical condition is psychiatric
3. Relationship may be complicated
4. Settings primarily geared towards identification/treatment of mental disorder may have a lower expectation for and familiarity with diagnosis of medical conditions

Question 7

What are 5 possible relationships between the etiology of the general medical condition and the psychiatric symptoms

Answer 7

1. Direct physiological effect on the brain
2. Through psychological mechanism
3. Medication for general medical condition —> Medication-Induced Mental Disorder
4. Psychiatric symptoms cause/adversely affect the general medical condition
5. They are coincidental

Question 8

2 clues suggesting that psychopathology is caused by direct physiological effect of a general medical condition

Answer 8

1. Nature of temporal relationship, vary in severity together and disappear when medical condition disappears
2. Psychiatric presentation is atypical in symptom pattern, age of onset or course

Question 9

What is the difference between an Other Specified Disorder and an Unspecified Disorder

Answer 9

In Other Specified Disorders the clinician chooses to specify the reason that symptomatic presentation does not conform to any of the specific disorder definitions, in Unspecified Disorders the clinicians don’t specify this

Question 10

What are 6 ways in which comorbid conditions may be related to each other

Answer 10

1. Condition A may cause or predispose to condition B
2. Condition B may cause or predispose to condition A
3. An underlying condition C may cause or predispose to both conditions A and B
4. Conditions A and B may, in fact, be part of a more complex unified syndrome that has been artificially split in the diagnostic system
5. The relationship between conditions A and B may be artifactually enhanced by definitional overlap
6. The comorbidity is the result of a chance co-occurrence that may be particularly likely for those conditions that have high base rate

Question 11

What are 3 considerations in determining whether there’s a causal relationship between substance and psychiatric symptoms

Answer 11

1. determine whether theres a temporal relationship between substance use and symptoms
   —> if onset symptoms precedes onset of substance, substance use is probably secondary or unimportant
   —> if onset substance use precedes onset of symptoms, suggests substance induced disorder
   —> if they happened simultaneously, determine what happens when substance has been removed; psychiatric symptoms should be attributed to substance if they remit within 1 month of the cessation
2. Consider whether the nature, amount and duration of substance/meds use are consistent with the development of the observed psychiatric symptoms
3. Consider factors in the presentation that suggest that the presentation is not caused by a substance