Verbal fluency deficits in geriatric and nongeriatric chronic schizophrenic patients

Schizophrenia in later life

This review provides a comprehensive overview of schizophrenia in older adults. We review the epidemiology, classification and psychopathology of schizophrenia in later life and summarize recent research findings on depression, cognitive functioning, medical illness, adaptive functioning, quality of life, caregiver issues, and pharmacological and nonpharmacological management. We discuss the implications of these findings for clinical care, public policy and future research.

Humor appreciation deficit in schizophrenia: the relevance of basic neurocognitive functioning

The purpose in undertaking the present study was to investigate humor appreciation in patients with schizophrenia. Moreover, we sought to explore the potential relationship of humor appreciation with measures of psychopathology and cognitive functioning among the patients. Thirty-six patients with schizophrenia were compared with 31 normal controls matched for age, sex, and education on a computerized test comprising captionless cartoons: Penn's Humor Appreciation Test (PHAT). The patients were also evaluated on the symptom dimensions derived from the Positive and Negative Symptom Scale (positive symptoms, negative symptoms, cognitive symptoms, depression, and excitement), as well as a battery of neuropsychological tests measuring executive functions, attention, working memory, verbal and visual memory, visuospatial ability, and psychomotor speed. Patients with schizophrenia had significantly lower scores on the PHAT than normal controls. The patients' performance on the PHAT correlated with scores on Penn's Continuous Performance Test, the Stroop Color-Word Test, and the phonological subscale of the Greek Verbal Fluency Test. Our findings indicated impaired humor appreciation among patients with schizophrenia. The relationship found between the appreciation of captionless cartoons involved an incongruous detail and performance on a broad neuropsychological battery suggested that the deficit in humor appreciation in schizophrenia could be attributed to impairment in more basic neurocognitive domains, namely, selective and sustained attention as well as phonological word fluency.

Verbal fluency in institutionalized patients with schizophrenia: age-related performance decline

Several studies have reported a relatively stable level of cognitive deficits among patients with schizophrenia regardless of age, while others have suggested continued deterioration with age. We compared the performance of 42 institutionalized patients with schizophrenia and 42 age- and education-matched healthy controls on a semantic and phonemic verbal fluency test. Each group was divided into young participants (<65 years old) and elderly participants (> or =65 years old). We found a fluency condition x diagnostic group x age group interaction on total words produced, a fluency condition x diagnostic group interaction on the number of cluster-related words, and a fluency condition x age group interaction on the number of switches. Patients with schizophrenia generally used similar strategies (i.e., semantic or phonemic cluster-related words and switches) as healthy individuals when generating words, but to a lesser degree. We found a disproportionate decline in the elderly schizophrenic patients relative to that of healthy controls only on the phonemic, relative to the semantic test. This decline in performance appears related to the effects of aging rather than severity or chronicity of illness, duration of institutionalization, or a progressive degenerative process associated with the disorder.

Word production deficits in schizophrenia

Fronto-cerebellar circuitry is implicated in word production. Data suggest that the cerebellum is involved in word search, whereas the prefrontal cortex underlies the selection of words from among competing alternatives. We explored the role of search and selection processes in word production deficits in schizophrenia patients. In Experiment 1, patients were impaired in a verb generation task under both high and low selection conditions but were more impaired in the high selection condition. In Experiment 2, when the difficulty level of search and selection conditions was equated in a word stem completion task, patients were only impaired in the search condition. Word search deficits underlie word production problems in schizophrenia, and may involve fronto-cerebellar dysfunction.

Cognitive impairment in elderly patients with schizophrenia: age related changes

Cognitive impairment in schizophrenia is a major feature of the illness. Like many of the other aspects of the illness, however, it has not been studied extensively in older patients. Several studies of older patients with a lifetime course of poor outcome and chronic institutional stay have indicated that some patients manifest evidence of profound cognitive impairments on a cross-sectional basis and cognitive and functional decline over longitudinal follow-ups of 30 months or longer. Risk factors for this decline include lower educational attainment and more severe positive symptoms, but do not include more severe symptoms of physical illness. These impairments have been shown to be discriminable from normal age-related changes and from the changes associated with Alzheimer's Disease. In contrast, studies of patients with no history of lifetime institutional stay find no such evidence of either age-related changes in cognitive functioning or longitudinal decline in cognitive or functional status. Since there is accumulating evidence of progressive brain changes over the lifespan in patients with schizophrenia, the course of cognitive deficits in later life will remain an important topic, both for understanding the lifetime course of schizophrenia and for developing interventions aimed at reduction of disability in the illness.