Comprehensive cognitive assessments are valuable for several reasons. First, they provide an objective measure of the person's cognitive functioning at a specific point in time. Second, by providing fully quantitative results, the testing is a very useful way to monitor change in response to treatment for patients with cognitive deficits. Third, neuropsychological tests may help to differentiate between organic or neurologic and psychiatric causes of cognitive problems. Fourth, an understanding of static deficits may help to guide the individual in the construction of alternate strategies to cope with cognitive deficits; for example, a person with auditory attention problems may do best with visually presented information.

Since subjective reports of cognitive difficulties, such as memory problems, do not always correlate with objective data, we cannot rely only on self-reported cognitive problems. A comprehensive selection of tests is administered, including measures of general intellectual functioning as well as specific areas of functioning such as verbal and visual memory and learning, attention/concentration, verbal fluency, processing speed, fine and gross motor functioning, and executive functioning is administered. The sensitivity of neuropsychological tests in identifying brain dysfunction is high, though the test deficits are not specific to Lyme Disease. Measures of psychopathology, particularly depression and anxiety are administered as well since affective states may affect cognitive performance .

Impairments in memory, attention and mental activation, language conceptual ability, and motor function have been documented in adults with LD. In particular, verbal memory deficits usually assessed by list-learning (Buschke Selective Reminding Test or the California Verbal Learning Test) have been found to be one of the most consistent problems in adults with LD. Studies by Kaplan, Krupp and others support the hypothesis that cognitive impairments are caused by CNS dysfunction and not secondary to a psychological response to chronic illness. Subjective memory impairments may however be higher in LD patients with comorbid depression, a finding which strengthens our recommendation that patients with depression should be monitored closely by a psychopharmacologist.