Schizophrenia executive function

A PDE10A inhibitor may also have the potential to treat the cognitive symptoms of schizophrenia. The principal evidence for this claim is papaverine reversal of a PCP-induced deficit in the EDID-set shifting assay in rats [35]. This assay translates into human behavior in the form of the Wisconsin Card Sorting Test (WCST). EDID-set shifting is a test of executive function, a measure in which schizophrenics have a robust deficit. It has also been shown recently that papaverine is efficacious in the Novel Object Recognition cognition assay [36]. 

Kravaiiti, E., Dixon, T., Frith, C., Murray, R., and McGuire, P. (2005) Association of symptoms and executive function in schizophrenia and bipolar disorder. Schizophr. Res. 74, 221-231. 

The deficit of cortico-striatal innervation that is presumably responsible for reported losses of striatal glutamate uptake sites (Aparicio-Legarza et al., 1997 Simpson et al., 1992), is likely to contribute to the cognitive dysfunction of schizophrenia. These have been described as having similarities to the subcortical dementia (Pantelis et al., 1992) seen in a variety of neurodegenerative disorders disturbances of corticostriatal function are thought to underlie this pattern of cognitive deficits that include disturbances of attention, executive function and short-term memory. 

By their nature, executive functions are quite complex. For this reason, computational (Cohen et al., 1996)/cognitive neuroscience (Carter et al., 2000 MacDonald and Carter, 2002 Carter and Barch, 2007) approaches have gained prominence in research focused on elucidating the role of abnormalities in this domain in schizophrenia. 

There were moderate but significant improvements in neurocognition (including executive function, working memory, and declarative memory) in a randomized, double -blind, 8-week study in 52 patients with schizophrenia assigned either to olanzapine (10-20 mg/day n = 18) or amisulpride (400-800 mg/day n = 18) (11). Of 16 dropouts, six were due to adverse events olanzapine—sedation (n = 2) and increased transaminases (n = 1) amisulpride—rash, extrapyramidal symptoms, and galactorrhea (n — 1 each). 

The negative symptoms of schizophrenia are the associated low-functioning executive functions, inattention, and poor interest levels the so-called positive symptoms are hallucinations and delusions. 

Psychosis, schizophrenia and bipolar disorder. In an investigation the relationship between brain Glu levels and cortical response during executive functioning in people at high risk for psychosis, Fusar-Poli et al discovered a lower level of Glu in the thalamus, which was associated with the extent of BOLD activation in various brain regions. 

In 70 patients with schizophrenia and persistent symptoms or troublesome adverse effects who were assigned to a flexible dosage (40-160 mg/day) in a 12-month open trial of ziprasidone looking for cognitive improvement, there were significant improvements in executive functions, attention, and information processing domains, but the effect sizes were moderate [138 j. 

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