‘I Can’t Think Clearly’: Diagnosing Traumatic Brain Injury with DSM-5

Edmundo is a 24-year-old veteran with no formal psychiatric history. He is hospitalized after his fiancé discovers a suicide note and a stockpile of Vicodin. On examination, Edmundo minimizes his distress. He denies all symptoms of depression, mania, psychosis, and posttraumatic stress disorder. He requests discharge, saying “It was just a bad night.” You remind him that he was admitted involuntarily and that you need additional information before you can safely release him.

An hour later, Edmundo’s nurse pages you to report that he became upset during an occupational therapy group and threw a game board across the room. When you return, Edmundo is pacing and cannot recall your name.

When you sit with Edmundo and ask about his family, he settles down quickly. He is the oldest of five children. He attended college on a ROTC scholarship, graduating with honors in engineering. He is engaged to marry his girlfriend of six years and had hoped to become a civil engineer after completing his military service. Since suffering a head injury six months prior during a combat mission, he has struggled to complete complex tasks. He apologizes for throwing the game board, saying “I can’t think clearly, and I was ashamed to have forgotten the rules of the game.” He admits to struggling at work and at home, asking “If I cannot follow a recipe to make dinner, how can I return to my unit?”

On examination, Edmundo is alert and fully oriented. He scores 25/30 on the Mini-Mental Status Examination, struggling with attention, calculation, and recall. You observe deficits in his processing speed, working memory, cognitive flexibility, and executive function. He admits that he finds it increasingly difficult to hide his deficits from his fiancȳe, his peers, and his family.

In DSM-IV, it is difficult for an interviewer to account diagnostically for Edmundo and his distress. Is he minimizing symptoms of a depressive, posttraumatic stress, or substance abuse disorder? Perhaps, but if an interviewer wishes to account for the deficits in memory and executive functioning that he or she observes on this initial encounter, the best DSM-IV diagnoses would be dementia due to head trauma on Axis I and head injury on Axis III.

An interviewer can make a more precise yet parsimonious diagnosis of Edmundo’s distress with DSM-5. After further testing, his DSM-5 diagnosis would likely be major neurocognitive disorder associated with traumatic brain injury. He is not delirious, but he has experienced a significant decline in his neurocognitive performance that reduces his independence. While his frustration culminated in suicidal ideation, his primary deficit is a neurocognitive disorder.

The authors of DSM-5 thoroughly updated our diagnostic categories. Consider the neurocognitive disorders, a category that is a model for future diagnostic systems. The authors organized the category around a central theme, an acquired deficit in neurocognitive function that signifies a marked decline from a person’s previous level of function, while encouraging a diagnostic interviewer to name the cause of a person’s neurocognitive impairment. So you can identify Alzheimer’s disease, Lewy body disease, traumatic brain injury, or another specific type. In this way, this DSM-5 category points to a future diagnostic system in which the symptoms of a psychiatric disorder and their etiology are integrated.

In the present, the use of neurocognitive disorder allows you to diagnose a young person like Edmundo without declaring that he or she has dementia, which implies global neurocognitive decline and is an illness associated with the elderly. Traumatic brain injuries are the characteristic injury of contemporary warfare, and the number of people with traumatic brain injuries is growing. By requiring a traumatic brain injury to be identified on both Axis I and III, DSM-IV-TR suggests a division between mind and body. By removing the multiaxial system, reconfiguring the diagnostic category, and encouraging the identification of etiology, DSM-5 allows us to give a more precise label to experiences like Edmundo’s.

Finally, the story of Edmundo reminds us that we cannot “think clearly” about another person just by asking a list of diagnostic questions. If we want to understand other people, we have to develop the habit of asking the right questions of the people we meet. ■