Many cancer patients experience impairments of neurocognitive function, inc
luding memory loss, distractibility, difficulty in performing multiple task
s (multitasking), and a myriad of other symptoms. Patients may also concurr
ently suffer from mood disturbance and symptoms that compromise their abili
ty to function adequately, including fatigue and pain. The etiologies of th
ese problems are diverse and include the direct effects of cancer within th
e central nervous system (CNS) indirect effects of certain cancers (eg, par
aneoplastic brain disorders), and both diffuse and highly specific effects
of cancer treatments on the brain, In addition to these cancer-related caus
es, patients may have coexisting neurologic or psychiatric disorders that a
ffect their cognition and mood. Careful assessment of patients complaining
of neurocognitive or behavioral problems is essential to providing appropri
ate interventions and maximizing their ability to carry out usual activitie
s.