Experimental Psychological Evaluation of Lack of Insight in Paranoid Schizophrenia Patients: Cognitive Function Assessment.

Abstract

The study attempted to experimentally evaluate cognitive correlates of lack of insight (understood as a metacognitive function — ability to recognize and correct erroneous decisions). The sample of patients with paranoid schizophrenia (N=100, mean age 33.2±8.1 years) was divided into two groups based on clinical indicators of insight: data about patients’ attitude to their erroneous decisions, personality and symptoms. Group characteristic: high insight n=61; low insight n=39. The assumption about factor structure of insight was made and factors were constructed by confirmatory factor analysis. The final model included 9 quantitative parameters of insight. The first factor included: Diligence, Interest to the Results, Adequate Understanding of purpose of survey, Response to comment, Response to help. The second — External control, Response to errors, Perception of instruction, Awareness to symptoms. Cognitive functioning were assessed by: Standard battery of neuropsychological assessment (subtests “Clock faces”, “Portraits”, series of plot pictures “Apple tree”, “Involuntary recall”, Poppelreuter Overlapping figures test, “Incomplete images”); Schulte table; Amatuni–Vasserman Digit cancellation test; The Wechsler adult intelligence scale (WAIS) (subtests “Similarities”, “Digit span”, “Digit symbol coding”); Zeigarnik Exclusion of items; Trail making test (TMT); Brief assessment of cognition in schizophrenia battery (BACS) (subtests “Verbal memory”, “Digit sequencing”, “Verbal fluency”, “Symbol coding”); Rey–Osterrieth Complex figure (ROCF); Hopkins verbal learning test (HVLT). The low insight patients showed poorer performance in various cognitive domains. Such as verbal learning and visual-motor memory, attention shifting, processing speed, executive function. In addition, the severity of lack of insight was significant for differences in number of distortions in visual perception task and severity of formal thought disorder. These results could be used in process of experimental insight assessment tools development and therapeutic interventions targeted on metacognitive deficit of schizophrenia patients.