Schizophrenia and Intellect
Thomas W. Weickert, Terry E. Goldberg, James M. Gold, Llewellen B. Bigelow,
Michael F. Egan, Daniel R. Weinberger
Presentation by: Bryan Lang
Caroline Helfrich and
Jessica Wright
Weickert, T. W., Goldberg, T. E., Gold, J. M., Bigelow, L. B., Egan, M. F., & Weinberger, D. R.
(2000). Cognitive impairments in patients with schizophrenia displaying preserved and
compromised intellect. Archives of General Psychiatry, 9(57), 907-913.
Hypothesis
That a group of intellectually declining patients
would display executive function, attention,
and memory deficits; and a group with
premorbid and morbid IQ deficits would
display a broader spectrum of cognitive
impairment.
Weickert, T. W., Goldberg, T. E., Gold, J. M., Bigelow, L. B., Egan, M. F., & Weinberger, D.
R. (2000). Cognitive impairments in patients with schizophrenia displaying preserved
and compromised intellect. Archives of General Psychiatry, 9(57), 907-913.
Background
• Although intellectual and neurocognitive
deficits accompany schizophrenia, there are
inconsistencies in the literature concerning
issue of intellectual decline, premorbid
deficits, a modal deficit pattern, and
preserved abilities
Weickert, T. W., Goldberg, T. E., Gold, J. M., Bigelow, L. B., Egan, M. F., & Weinberger, D.
R. (2000). Cognitive impairments in patients with schizophrenia displaying preserved
and compromised intellect. Archives of General Psychiatry, 9(57), 907-913.
Methods
• Neuropsychological tests were administered
to 117 patients with chronic schizophrenia
and a group of 27 healthy control subjects to
examine patterns of premorbid and current
intellect
• Healthy control subjects were the comparison
group to establish the degree to which
schizophrenia patients deviate from normal
ones on cognitive levels
Weickert, T. W., Goldberg, T. E., Gold, J. M., Bigelow, L. B., Egan, M. F., & Weinberger, D. R.
(2000). Cognitive impairments in patients with schizophrenia displaying preserved and
compromised intellect. Archives of General Psychiatry, 9(57), 907-913.
Results
• 60 patients with schizophrenia who displayed a general
intellectual decline of 10 points or greater from estimated
premorbid levels also exhibited deficits of executive
function, memory, and attention
• 28 patients with schizophrenia with consistently low
estimated premorbid intellect and current intellectual
levels who displayed no evidence of IQ decline exhibited
language and visual processing deficits in addition to
deficits present in the intellectually declining group
• The remaining 29 patients who displayed average
estimated premorbid intellectual levels did not show a
decline in IQ and exhibited a relatively normal cognitive
profile, with the exception of executive function and
attention impairment
Weickert, T. W., Goldberg, T. E., Gold, J. M., Bigelow, L. B., Egan, M. F., & Weinberger, D. R. (2000). Cognitive
impairments in patients with schizophrenia displaying preserved and compromised intellect. Archives of General
Psychiatry, 9(57), 907-913.
Conclusions
• These results suggest that IQ decline, although
modal in schizophrenia, is not universally
characteristic and that executive function and
attention deficits may be core features of
schizophrenia, independent of IQ variations
• A large minority of patients (25%) were
intellectually intact
Weickert, T. W., Goldberg, T. E., Gold, J. M., Bigelow, L. B., Egan, M. F., & Weinberger, D.
R. (2000). Cognitive impairments in patients with schizophrenia displaying preserved
and compromised intellect. Archives of General Psychiatry, 9(57), 907-913.
Critical Review Items: 3 Interesting
Points
•
1. It was interesting to see that no matter what intellectual group the participants
were put into, all of the schizophrenic participants had some type of executive
function or attention deficit. These deficits were independent from the IQ
variations and could be a possible insight into the central characteristics of
schizophrenia.
•
2. Even though there was an unexpected large minority of participants that
showed to be intellectually intact, interesting conclusions were still drawn from
them. First, the authors of the study were able to prove further that antipsychotic
drugs don’t always have an effect on performance on cognitive tests. They also
showed that individuals diagnosed with chronic schizophrenia can be cognitively
unaffected in all areas other than executive functioning and attention.
•
3. Overall, we believe that the authors of this study did a thorough job testing the
cognitive abilities of the participants. The participants were tested on their
memory, verbal retrieval, lexical integrity, attention, executive functioning, set
shifting, perceptual abilities, psychomotor speed and motor speed. After seeing all
of the results of the tests, it is safe to say that this study gave us a better
understanding of schizophrenia and cognitive decline.
Weickert, T. W., Goldberg, T. E., Gold, J. M., Bigelow, L. B., Egan, M. F., & Weinberger, D. R. (2000). Cognitive
impairments in patients with schizophrenia displaying preserved and compromised intellect. Archives of
General Psychiatry, 9(57), 907-913.
Critical Review Items: 3 Weak/Unclear
Points
•
1. Because this study only included tests done on the participants after the onset
of schizophrenia, we find it hard to understand how you can directly compare the
results to previous IQ estimates done on the participants. We think the study
would have been stronger if it was a longitudinal and had IQ scores from both
before and after the onset of the disorder.
•
2. Similar to the point above, it would have been interesting to see a longitudinal
study of the participants to better understand the cognitive and intellectual
deficits over time. All this study proves is that there are cognitive and intellectual
deficits, but not when the onset of the deficits occurred. Knowing when and how
the deficits occur would be much more beneficial to know when regarding
treatment of the disorder.
•
3. The last thing that we would alter in this study is how the researchers tested the
participants. Because there are so many extensive tests done all in one session, we
believe that the possibility of the participants being overwhelmed or drained
would negatively affect test scores. Having the tests conducted over a couple of
different sessions would help eliminate this problem.
Weickert, T. W., Goldberg, T. E., Gold, J. M., Bigelow, L. B., Egan, M. F., & Weinberger, D. R. (2000). Cognitive impairments
in patients with schizophrenia displaying preserved and compromised intellect. Archives of General Psychiatry, 9(57),
907-913.
Video: Jani Loses Touch With Reality
(example of short attention span)
• http://www.youtube.com/watch?v=WjqRYgIC
gdU
Weickert, T. W., Goldberg, T. E., Gold, J. M., Bigelow, L. B., Egan, M. F., & Weinberger, D. R.
(2000). Cognitive impairments in patients with schizophrenia displaying preserved and
compromised intellect. Archives of General Psychiatry, 9(57), 907-913.