Differential diagnosis Flashcards
what are the 6 steps in the process of differential diagnosis?
- ruling out malingering and factitious disorder
- ruling out substance etiology
- ruling out an etiological medical condition
- determining the specific independent mental disorders
- differentiating Adjustment Disorders from the residual Other Specified and Unspecified conditions
- establishing the boundary with no mental disorder
how is malingering and factitious disorder similar and different? (4)
- both characterized by feigning the presenting symptoms
- they are differentiated based on the motivation for the deception
- motivation -> achievement of a clearly recognizable goal (insurance money) -> malingering
- deceptive bhvr present even in absence of obvious external rewards -> factitious disorder
when should the clinician raise suspicion for malingering or factitious disorder? (5)
- clear external incentives present for the psych diagnosis (forensic evaluations)
- the patient presents with a cluster of symptoms conforming more to a lay perception of MHD rather than a recognized clinical entity
- the nature of the symptoms shift from one clinical encounter to another
- patients’ presentations mimics a role model (another patient in the unit, mentally ill family member)
- patient characteristically manipulative or suggestible
what is the single most common diagnostic error? (1)
- missing a substance etiology
the fact that substance use and psychopathology occur together _______ a cause-and-effect relationship between them.
the fact that substance use and psychopathology occur together does not necessarily imply a cause-and-effect relationship between them
when in step 2 >, what are then within tasks»_space; ? (1,2 -123, 3)
- determine whether the person uses (history taking, physical examination, family member consultation…)
- once substance use established, the determination whether there is an etiological relationship with the psych symp (3 options)
- psych symptoms directly caused by the effects of substance on CNS
- substance use is a consequence of a primary psych dis
- psych symp and su are independent
- after deciding that a presentation is due to the direct effects of a substance, determine which DSM substance/medication-induced mental disorder best describes the presentation
in step 2, > when considering that su is a consequence (rather than a cause) of the psych symptomatology»_space; what is the hallmark of its presence? (1)
- the independent psychiatric disorder occurs first and/or exists at times during the person’s lifetime when they are not using any substance
(in DSM 5 TR, why is the phrase ‘medical condition’ modified with adjectives such as another, other, general…? (1)
- to clarify the etiological condition being, like a mental condition, is a medical condition different from a psychiatric medical condition by being nonpsychiatric by virtue
in step 5, > how to decide whether adjustment dis or one of the residual other specified or unspecified categories should be considered? (2)
- if the symptoms developed as a maladaptive response to a psychocsocial stressor -> adjustment dis
- if a stressor is not responsible for the development of the clinically sig symptoms -> other specified/unspecified category
in step 5, > how to decide between other specified or unspecified mental disorder? (2)
- if the clinician indicates the specific reason that the symptomatic presentation does not meet the criteria -> other specified (mental dis)
- if the clinician does not indicate a specific reason to why it does not conform -> unspecified (mental dis)
in step 2 > when considering that psych symptoms are directly caused by the effects of substance on CNS,»_space; what are the 3 considerations»_space;>?
- consider a temporal relationship between substance/medication use and the onset/maintenance of the psychopathology
- determine the likelihood that the pattern of substance/medication use can account for the symptoms (looking at nature, amount, duration…)
- consider other factors in the presentation that suggest other causes than a substance/medication
in step 2, > when considering that psych symptoms are directly caused by the effects of substance on CNS and»_space; when further considering the temporal relationship between substance/medication use and the onset/maintenance of the psychopathology»_space;> , what are the steps u do»_space;»? (4)
- psych symp present before su or did they closely precede su?
- did both start more or less simultaneously? -> waiting for what happens after a period of abstinence after the withdrawal phase -> if persistance, then psychopathology not primary and not due to su (exceptions are Persistent type of Substance/Medication-Induced Major or Mild Neurocognitive Disorder and Hallucinogen Persisting Perception Disorder)
- suggested time of abstinence is 1 month (but flexible
- if the person does not remember at all, then assistance during abstinence (maybe even in a controlled setting)
in step 2, > when considering that both the psychiatric dis and the su can be initially unrelated»_space; what do you have to do first? (2)
- you have to rule out a causal relationship
- it’s more likely to be ruled out if there are periods when the psychiatric symptoms occur in the absence of su and if the su occurs at times unrelated to the psychiatric symptomatology
in step 3, > what are the 4 reasons why differential diagnosis can be difficult?
- symptoms of some psych dis and many non psych dis can be identical
- sometimes the first presenting symptoms of a medical condition are psychiatric
- the relationship between the non psych medical condition and the psych symptoms can be complicated (e.g. anxiety as a reaction to having a non psych condition vs the medical condition being a cause of the anxiety)
- psych patients often in settings geared towards identification of mental disorders, where there may be lower expectation for a diagnosis of medical conditions
in step 3 >, what is meant by ‘mental disorder due to another medical condition? (3)
- e.g. depressive dis due to hypothyroidism (Depressive Disorder Due to Another Medical Condition)
- virutally any psych dis can be caused by the direct physiological effects of a nonpsych medical condition
- important to direct the history, physical examination toward the diagnosis of those nonpsych medical conditions that are most commonly encountered and most likely to account for the presenting psych symptoms
in step 3, > what are the 5 possible relationships of the potentially established medical condition to the, if any, psych symptoms? (+1)
- the nonpsych medical condition causes the psych symptoms through a direct effect on the brain
- the nonpsych medical condition causes the psych symptoms through a psychological mechanism (e.g. depression as a reaction to a cancer diagnosis)
- medication for the nonpsych medical condition causes the psych symptoms
- the psych symptoms cause the nonpsych medical condition
- the psych symptoms and the nonpsych medical condition are coincidental
(In the real clinical world, however, several of these relationships may occur simultaneously with a multifactorial etiology)
in step 3, > what are the 2 clues suggesting that psychopathology is caused by the direct physiological effect of a nonpsych medical condition? What is, however, important to keep in mind regarding these 2 clues? (1 - 2, 2 - 1)
- nature of the temporal relationship
- this clue does not establish that the relationship is physiological
- psych symptoms may manifest also relatively late (months, years) after the nonpsych medical condition established (e.g. depression in parkinsons) - whether the psych presentation is atypical in symptom pattern, age, onset or course
- atypicality in itself does not indicate a nonpsych medical etilolgy
in step 5, > when is a diagnosis of adjustment dis, residual other specified or unspecified mental dis considered? (1)
- when the clinical presentation does not conform to the particular symptom pattern in DSM 5 TR diagnostic criteria or they fall below the established severity/duration thresholds BUT they are still severe enough to cause clinically significant impairment
in step 6, > what is the common criterion DSM uses to establish a mental dis diagnosis? + an example
- more or less - “The disturbance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning.”
Example: i.e. a diagnosis of Male Hypoactive Sexual Desire Disorder, including the requirement of a low sexual desire causing clinically significant distress in the individual, would not be made in a man with low sexual desire who is not currently in a relationship and who is not particularly bothered by the low desire
in step 6, > what does ‘clinically significant’ mean in “The disturbance causes clinically significant distress or impairment in social, occupational, or other important areas of functioning.”, what is the rule of thumb? (2)
- what means clinically significant can be defined only by a clinician but in a clinical mental health setting, it’s normally not an issue as the fact that the individual has sought help automatically makes it “clinically significant.”
- what is normally challenging is if the symptomatic picture is discovered in the course of treating another mental dis or a nonpsych medical condition which is common due to the comorbidity -> then the rule of thumb is if the comorbid psychiatric presentation warrants clinical attention and treatment, it is considered to be clinically significant
