The standard diagnostic manual in psychiatry is the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). This manual presents a categorical system with agreed-upon lists of symptoms. However, it is sometimes difficult for the clinician to identify the appropriate list when faced with a patient who has psychiatric symptoms. This chapter provides the information needed to organize a differential diagnosis for a patient with a neurologic disorder having psychiatric manifestations, which can then be elaborated and verified by consulting the DSM-5.
APPROACH TO THE PSYCHIATRIC PATIENT
Mental status examination is observation of a patient’s language function and behavior that reflects on his or her mental function. Particularly crucial is understanding how the patient organizes and expresses information. The mental status examination can be performed by observing the patient’s organization of information in the telling of his or her history. The patient should organize the history spontaneously as a story, with logic and sequence, and provide emotional commentary.
Logical thinking includes especially the categorization, sequencing, and logical relationship of data, events, and ideas. The illness history should be told by the patient in a reasonably organized and understandably sequential form. Facts and feelings about facts should be relatively separate. The patient should be able to demonstrate the capacity for abstract thinking in his or her categorization of the facts of the narrative. The patient also should be able to flexibly move back and forth both sequentially and between the different levels of abstraction.
Observation of the patient’s narrative can tell the clinician a great deal about memory function, as reflected in consistency of data information and its time sequencing. Consistency of narrative reveals working memory capacity, flexibility of information manipulation, access to long-term memory storage, and ability to maintain connection to the examiner and the questions.
Emotion is another major faculty observed and examined, including whether affect is modulated, controllable, and linked to cognition. When a devastating story of illness is told by the patient, an appropriate affect should be observable.
When one dominant affect influences all mental contents, it is called mood. Mood is observed both in its breadth and in its depth. As mood becomes more intense, its range of included topic areas broadens, and it is more deeply felt.
Attitude refers to a dominant emotional theme affecting interpersonal relationships. Attitude is observable in the narrative history as well as in the patient’s developing relationship with the clinician.
Another category of mental faculty is behavior. The clinician observes whether impulse control of behavior is rigid or disinhibited. This affects the appropriateness of social interactions and, again, may be observable in language behavior and in social behavior with the clinician.
A cognitive function meriting special observation and perhaps specific examination ...