Anne L. Hoff
University of California Davis School of Medicine
UC Davis Napa Psychiatric Research Center
Schizophrenia has been considered a disorder involving cognitive deficits from its earliest description. Kraepelin described it as a “disorder of attention” and eventually coined the term “dementia praecox” to describe the deteriorating course of illness, which resembled an organic dementia in some patients ( 1). With the advent of antipsychotic medications in the 1950s, it is now rare to observe the natural course of schizophrenic illness over a lifetime. Indeed, there is evidence to suggest that antipsychotic medications improve outcome. A group of recent studies suggest that longer duration of untreated psychosis is associated with a longer period of recovery, more negative symptoms, and worse social or occupational functioning ( 2 , 3).
What are cognitive deficits in schizophrenia and how are they measured? Cognitive deficits involve mental-processing capacities that range from elementary processes such as simple attention and vigilance to more complex processes such as abstract thinking and higher-order problem solving. The field of neuropsychology that originally focused on the effects of brain damage (from missile wounds, tumors, head