Medical School

Postgraduate research profiles


Kirsty Scholes

Start date

Mar 2006

Submission date

Mar 2010

Kirsty Scholes


The effects of chronic cannabis use on Prepulse Inhibition and Cognition in healthy individuals and patients with schizophrenia


The auditory startle reflex is series of muscular contractions in response to a sudden, loud auditory stimulus. The size of this reflex is reduced when a quieter sound (prepulse) is presented just before the loud startling sound (pulse); this is called prepulse inhibition (PPI). It has been shown that patients with psychiatric illnesses such as schizophrenia have a reduction in PPI. However, the basis for this reduction is a matter of debate, with some studies suggesting that this deficit results from a disruption to preattentive information processing, while others suggesting that this disruption is secondary to dysfunction of selective attention. Therefore, this thesis aims to use improved methodology to examine the nature PPI in schizophrenic patients, in an attempt to further understand the basis of alterations to PPI in patients. Further, given the hypothesised associated between schizophrenia and cannabis use, and the apparent similarities in cognitive and psychophysiological dysfunction that are evident in both patients with schizophrenia and healthy cannabis users, this thesis will examine the effects of chronic cannabis use on PPI and cognition in both patients with schizophrenia and healthy individuals.

Why my research is important

PPI is an important endophenotype of schizophrenia, and this research will assist in understanding of the underlying causes alterations in PPI, and thus may provide indications as to how to treat these alterations in schizophrenia. Further, the nature of the relationship between cannabis use and schizophrenia is very controversial, and this research will assist in the understanding of this relationship, which can help to guide public policy on cannabis use and treatment of patients with schizophrenia who use cannabis.