In this case, one needs to determine whether the cognitive or affective deficits are dominant. Patients suffering from a bipolar disorder may simulate a hyperactive delirious state while in their manic phase but the presence of grandiosity and euphoria and the history of depression will help establish the correct diagnosis. True pseudodementia, that is cognitive deficits due to depression, is uncommon. More often, dementia and depression coexist, especially during early stages of dementia. Therefore, the task of the physician is not to choose between dementia and depression but to determine whether either or both exist.
Drugs are the most common cause of treatment-induced depression.
Among the wide variety of drugs that can produce symptoms of depression, antihypertensive agents, particularly centrally acting alpha agents and beta blockers, and sedatives are probably the most common. Steroids, antiparkinsonism drugs, and narcotic analgesics are also common offenders. I n addition to the mental status features described above, the physical examination of a patient suspected of depression must include a standard neurologic examination, focusing on focal neurological deficits, language, gait, incontinence and sensory impairment. Laboratory tests are necessary to establish the presence of medical illnesses associated with depression. When used as screening tests of depression, head CT scanning, electroencephalography and chest radiography have seldom been shown to affect management.