Cognitive Functioning in Adults and Young People
Diagnosed with Schizophrenia.
Summary
The Mental Health
Foundation funded two research projects at the Institute of Psychiatry concerned
with the difficulties that people diagnosed with schizophrenia experience with
some cognitive tasks (thinking, memory, language). These projects aimed to
increase understanding of the causes of cognitive difficulty and to evaluate
ways of improving cognitive performance.
• Study 1 used state-of-the-art
functional magnetic resonance imaging (fMRI) scanning techniques to explore
whether people diagnosed with schizophrenia and their close relatives (identical
twins) show similarly unusual patterns of brain activity when carrying out
language tasks.
• Both people diagnosed with schizophrenia and their twin
brothers/sisters showed unusual patterns of brain activity when performing
verbal fluency tasks. This suggests that unusual brain activity during this task
may be related to genetic vulnerability to schizophrenia, as opposed to
schizophrenia per se.
• People diagnosed with schizophrenia also had
difficulty in identifying their own distorted speech, but their relatives who
had no experience of psychosis did not show this difficulty. This task may,
therefore be able to discriminate between people with a genetic risk and people
who have actually experienced psychosis.
• Study 2 was an evaluation of
Cognitive Remediation Therapy (CRT), with young people diagnosed with
schizophrenia at a relatively young age. CRT uses guided mental exercises to
improve thinking, concentration and memory.
• CRT was associated with
significant additional improvements in the young peoples memory and flexibility
of thinking.
• CRT has the potential to improve the quality of life of young
people recovering from an episode of psychosis. The researchers are continuing
to analyze data from additional participants in order to increase the power of
the study.
Background
People are usually diagnosed with schizophrenia
because they have had psychotic experiences, such as hearing voices or holding
bizarre beliefs. However, people with schizophrenia have also been found to
differ from other people on measures of brain activity when performing certain
cognitive tasks. For example, when asked to think of words beginning with a
certain letter (the verbal fluency task) people diagnosed with schizophrenia
tend to show unusual patterns of activation in the prefrontal cortex.
Difficulties on cognitive tasks (attention, memory and problem solving) can
affect recovery, by making it hard for someone to return to education or work.
Although anti-psychotic drugs can be very helpful in controlling psychotic
experiences such as delusions and hallucinations, they have little impact on
problems of thinking and memory. Cognitive remediation therapy (CRT) has been
used with adults to improve their cognitive performance, but hitherto it has not
been evaluated with younger age groups.
The Research: STUDY 1
An MRI
investigation of fronto-temporal network dysfunction in
schizophrenia.
Vivienne Curtis, Robin Murray & Philip McGuire, of the
Institute of Psychiatry, London, used MRI to examine whether people diagnosed
with schizophrenia and their close relatives have difficulties in carrying out
certain cognitive tasks, or show unusual brain activity when doing so. The aim
was to learn more about how genetic and environmental factors influence brain
function and the risk of psychotic experiences.