Posts Tagged ‘cognition’

Cognition and Depression

December 27th, 2010

Someday psychiatric diagnoses will entail biological tests. Today we rely on clinical knowledge.

Cognitive function can suffer when someone is depressed. Depressed patients often have trouble concentrating. Their minds wander. They are less productive, more distractible. But some elements of memory or cognitive dysfunction suggest other diagnoses.

Some years back I took a phone call from a university administrator in his late 60s. He had driven up to the keypad in his gated home and had forgotten the numeric combination. He assumed it was the stress he was under and that he should talk to me, a psychiatrist. Anxiety, depression, stress—none of these sounded right to me as an explanation of forgetting an over-learned four-digit code he used daily. I asked him to see his primary-care doctor immediately, and to be safe, I talked to his physician with the same sense of urgency. It turned out his blood pressure was extremely high (that’s where the stress factored in). He had experienced an encephalopathy. When his blood pressure returned to normal, his
cognition and memory also normalized.

The other day I got a call from an internist at my medical college. An 80-year-old patient who was also a long-time friend was upset about his son’s choice of a partner. The man’s wife believed he was depressed and phoned my colleague requesting that he prescribe an antidepressant for her husband. He preferred that his patient talk to a psychiatrist first. I phoned the man and was troubled when he described symptoms he attributed to family tensions. Having been married for over 40 years, he had recently called his wife by a wrong name several times. And when she drove to pick him up a day earlier, at first he didn’t recognize her. As in the case above, these sounded more “organic” to me. Differential
diagnoses that came to my mind included primary and secondary brain tumors (possibly setting off seizures), hypertension, other encephalopathies. Sometimes Alzheimer’s or other dementias begin in a stuttering fashion. In any case, the mental lapses he was experiencing didn’t sound to me like depression.

But when I met him in person, the picture changed. Showing a full and appropriate range of affect in the interview, and able to describe pleasurable activities with passion and relish, he was not depressed. Moreover, his short- and long-term memory and executive functions were impressive. Perhaps he would develop dementia over the coming years, as many people over 80 years do—but he wasn’t demonstrating it today. Instead, he described mounting marital tensions. At the end of my consultation, we discussed how he and his wife might address these. (His internist saw him and ordered additional tests. All were negative.)

Someday psychiatric diagnoses will entail biological tests. Today we rely on clinical knowledge.

- Alan J. Gelenberg, M.D.
Editor,
Biological Therapies in Psychiatry
Professor and Chair, Psychiatry, Penn State University
Editor-in-Chief,
Journal of Clinical Psychiatry