NEURAL CIRCUITRY UNDERLYING IMPAIRED INSIGHT IN SCHIZOPHRENIA: AN FMRI STUDY

1
NEURAL CIRCUITRY UNDERLYING IMPAIRED INSIGHT IN
SCHIZOPHRENIAAN FMRI STUDY

• Mark Benton
• Department of Psychiatry and Behavioral
  Neuroscience

2
What is Schizophrenia?

• Schizophrenia is a severe and debilitating mental
  illness (from Greek, meaning split mind).
• People with schizophrenia suffer terrifying
  symptoms
• hearing voices that others cannot hear
• fearing that people are plotting to harm them
• hallucinations
• Affects approximately 1 of the population.

3
What is Insight?

• Insight refers to several aspects regarding
  awareness of a mental illness
• awareness of the illness itself
• the social consequences of the illness
• the need for treatment
• correct attribution of symptoms to the illness
• Schizophrenia patients who lack insight do not
  believe that their positive symptoms (i.e.
  delusions, hallucinations) are caused by their
  illness.

4
Why study schizophrenia and insight?

• Schizophrenia patients who lack insight have poor
  clinical outcomes.
• Recent studies point to specific neurocognitive
  deficits and structural abnormalities associated
  with poor insight (Shad et al. 2004).

These observations underlie the need to examine
regional alterations in brain function,
specifically in the prefrontal cortex, in
patients with poor insight.
5
How can you study Insight and Schizophrenia with
fMRI?

• Use a paradigm designed to provoke
  self-evaluation using trait adjectives.
• Schmitz et al. 2004 used this same paradigm in a
  group of healthy control subjects. However, there
  have been no published reports using this task in
  any psychiatric population.
• Are the brain regions activated during this task
  the same in schizophrenics and healthy controls?
  If not, how do they differ?
• Do we see functional impairments (i.e. reduced
  activation) in areas of the brain previously
  implicated in insight impairment, namely the
  DLPFC?

6
I am
Shy
NO
YES
7
MARK is
Likeable
NO
YES
8
Is this word positive ?
Intelligent
NO
YES
9
Preliminary Findings

• N 4

SELF vs. WORD OTHER vs. WORD SELF vs. OTHER
10
Future Directions

• Evaluating oneself, compared to evaluating a
  close friend or relative, activates the dorsal
  lateral prefrontal cortex (DLPFC)
• Executive function
• Self-monitoring
• Conceptual organization
• Working memory
• This is an area of the brain shown to have
  decreased volumes in patients with poor insight
  (Shad et al. 2004).
• Now that we have replicated previous findings and
  shown such a study is feasible, we intend to
  continue scanning SZ subjects with poor insight.