Cognitive dysfunction in schizophrenia: a new set of tools for the assessment of cognition and drug effects.
Cognitive impairment in schizophrenia must be seen as a disturbance of cortico-sub-cortical connectivity with a neurotransmitter imbalance in a circuitry system, which connects thalamic input with prefrontal processing and supplementary motor cortex and basal ganglia output. The concept of maze-solving behaviour as a continuous cognitive task evoking a conflict between prefrontal cortex and basal ganglia activity is explained and introduced to distinguish between the effects of D2 blocking agents and substances with a predominant 5HT2A receptor affinity, such as clozapine and risperidone. Complex mazes show a cognitive deficit in untreated schizophrenic patients that are impaired by conventional and improved by atypical antipsychotic substances. Processing speed improves most on clozapine, while parallel processing is best supported by the non-sedative atypical substance risperidone. Maze paradigms are presented.
Gallhofer
B
B
Centre for Psychiatry, Justus-Liebig-University Medical School, Giessen, Germany.
Lis
S
S
Meyer-Lindenberg
A
A
Krieger
S
S
D014150:Antipsychotic Agents / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects* / Q000503:physiopathology; D003071:Cognition / Q000187:drug effects; D003072:Cognition Disorders / Q000175:diagnosis* / Q000503:physiopathology; D003657:Decision Making / Q000187:drug effects / Q000502:physiology; D006801:Humans; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D008959:Models, Neurological; D009483:Neuropsychological Tests; D018377:Neurotransmitter Agents / Q000502:physiology; D011340:Problem Solving / Q000187:drug effects / Q000502:physiology; D012559:Schizophrenia / Q000188:drug therapy / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D013028:Space Perception / Q000187:drug effects / Q000502:physiology
D014150:Antipsychotic Agents; D018377:Neurotransmitter Agents