Personality traits and cognitive ability in individuals with schizophrenia, bipolar disorder

141 Pages·2015·0.93 MB·English

UCLA
UCLA Electronic Theses and Dissertations
Title
Personality traits and cognitive ability in individuals with schizophrenia, bipolar disorder,
attention-deficit/hyperactivity disorder, and community participants.
Permalink
https://escholarship.org/uc/item/8nd4h44v
Author
Zvinyatskovskiy, Aleksey
Publication Date
2015

Peer reviewed|Thesis/dissertation
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University of California
UNIVERSITY OF CALIFORNIA
Los Angeles

Personality traits and cognitive ability in individuals with schizophrenia, bipolar disorder,
attention-deficit/hyperactivity disorder, and community participants.

A dissertation submitted in partial satisfaction of the
requirements for the degree Doctor of Philosophy in Psychology

by

Aleksey Zvinyatskovskiy

2015
ABSTRACT OF THE DISSERTAION
Personality traits and cognitive ability in individuals with schizophrenia, bipolar disorder,
attention-deficit/hyperactivity disorder, and community participants.

by

Aleksey Zvinyatskovskiy
Doctor of Philosophy in Psychology
University of California, Los Angeles, 2015
Professor Robert M. Bilder, Co-chair
Professor Steven Paul Reise, Co-chair

Cognitive ability and personality traits usefully characterize psychopathology across
individuals presenting with schizophrenia, bipolar disorder, and ADHD as well as the general
population. Working memory and executive functioning are two putative markers of
neurobiological impairment associated with pathology in these disorders. Impulsivity and
schizotypy are personality traits related to symptoms of mental illness. Although relationships
between cognitive ability and personality have been examined in the past, it is unclear whether
these relationships are similar in individuals with mental illness and the general population. The
present study examined the relationship between cognitive ability and personality traits in
individuals with mental illness and community participants. First, we carried out a hierarchical
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clustering and factor analysis procedures to aid in data reduction and confirm the factor
structure of personality scales used in the study. Data were collected using measures of
working memory, executive functioning, impulsivity, and schizotypy from individuals with
mental illness (53 with schizophrenia, 47 with bipolar disorder, and 46 with attention-
deficit/hyperactivity disorder) and 941 participants recruited from the community. Moderated
regression analyses were carried out to examine whether the relationship between impulsivity
and executive functioning was similar in individuals with bipolar disorder and ADHD compared
to community participants; and whether the relationship between schizotypy and working
memory was similar in individuals with schizophrenia and bipolar disorder compared to
community participants. Our study found that despite being developed to assess different
aspects of impulsivity, popular self-report impulsivity scales measure similar aspects of the
impulsivity construct. We also found that the three schizotypy scales in our study measure
three separate constructs, a result contrary to prior findings. Finally, almost all personality traits
had a similar relationship with cognitive ability in individuals with mental illness and community
participants. The exception was physical anhedonia, which showed a significantly stronger
negative relationship with working memory in individuals with schizophrenia, but not in
individuals with bipolar disorder, than in community participants. While additional evidence is
necessary to understand the likely underlying mechanisms of this difference, this finding shows
that the relationship between these traits is not equivalent between individuals with
schizophrenia and community participants.

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The dissertation of Aleksey Zvinyatskovskiy is approved.

Michael F. Green
Steve S. Lee
Robert M. Bilder, Committee Co-chair
Steven Paul Reise, Committee Co-chair

University of California, Los Angeles
2015

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DEDICATION

To my parents, Svetlana and Roman, to my sister, Oksana, and to Clara:
without their belief in me and countless sacrifices, none of this would be possible.
To my advisors, teachers, and especially to Bob and Steve:
thank you for teaching me how to think well.

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TABLE OF CONTENTS
Introduction……………………………………………………………………………………………………………………………….1
Cognitive Ability……………………………………………………………………………………………………………..3
Generalized cognitive impairment..……………………………………………………………..…….4
Memory impairment…………………………………………………………………………………………..9
Executive functioning impairment…………………………………………………………………...15
Summary.………………………………………………………………………………………………………….19
Personality Traits………………………………….………………………………………………………………………20
Impulsivity………………………………..………………………………………………………………………21
Schizotypy…………………………………………………………………………………………………………28
Summary…………………………………………………………………………………………………………..34
Present Study……………………………………………………………………………………………………………….35
Mental illness grouping…………………………………………………………………………………….36
Item parceling…………………………………………………………………………………………………..39
Study questions………………………………………………………………………………………………..40
Methods………………………………………………………………………………………………………………………………….42
Participants………………………………………………………………………………………………………………….42
Procedures………………………………………………………………………………….……………………………….44
Personality Measures……………………………………………………………………….………………………….44
Impulsivity………………………………………………………………………………………………………..44
Schizotypy…………………………………………………………………………………………………………46
Neuropsychological Measures………………………………………………………………….………………….46
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Analysis Plan…………………………………………………………………………………….………………………….48
Hierarchical clustering………………………………………………………………………………………………….48
Factor analysis in controls…………………………………………………………………………………………….48
Moderated multiple regression……………………………………………………………………………………50
Results………………………………………………………………………………………………………….………………………….52
Hierarchical Clustering………………………………………………………………………………………………….52
Factor Analysis of Individual Scales………………………………………………………..…………………….52
Factor Analysis Across Measures Within a Single Domain…..…………………………….………….55
Moderated Multiple Regression Analysis……………………………………………………….…………….56
Analysis across diagnostic groups……………………………………………………………………..56
Analysis within single diagnostic groups……………………………………………………………58
Discussion………………………………………………………………………………………………………………………….…….62
Individual Scale Analysis……………………………………………………………………………………………….63
Factor Analysis Across Scales………………………………………………………….…………………………….66
Impulsivity scales………………………………………………………………………………………………66
Schizotypy scales………………………………………………………………………………………………67
Moderated Multiple Regression…………………………………………………………………….…………….69
Analysis across diagnostic groups……………………………………………………………………..69
Analysis within diagnostic groups……………………………………………………………………..71
Limitations…………………………………………………………………..……………………………………………….74
Conclusions………………………………………………………………………………………………………………….77
Tables and Figures……………………………………………………………………………………………………………………79
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References…………………………………………………………………………………………………………………………….108

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