{"id":{"repo_id":"kings","oai_identifier":"oai:kclpure.kcl.ac.uk:studenttheses/9d70beb1-9b58-4143-9bc6-87065b64866b"},"canonical_url":"https://search.dev.ndltd.org/etd/kings/oai:kclpure.kcl.ac.uk:studenttheses/9d70beb1-9b58-4143-9bc6-87065b64866b","repository":{"repo_id":"kings","name":"King's College London","base_url":"https://kclpure.kcl.ac.uk/ws/oai"},"display":{"title":"Patterns of cannabis use in first-episode psychosis","abstract":"There is ample evidence that patients with psychosis are more likely to
use illicit substances than the general population, with cannabis being the most
popular. Research has also shown that cannabis use is associated with poor
prognostic outcomes in patients with an established psychotic disorder. It is
important to understand the reasons patients with psychosis endorse for their
cannabis use and findings so far point towards an ‘alleviation of dysphoria’ model
rather than the ‘self-medication’ hypothesis. It is not known how the level of
motivation to change cannabis use can affect patients’ actual use. Lack of
validated readiness to change questionnaires for use with psychotic populations
makes it essential to develop and validate such measures.
The aim of this thesis was to evaluate the reasons for cannabis use and its
effects on psychotic outcomes in a patient cohort with first-episode psychosis.
The association between cannabis use and other illicit drug use was also
investigated. Readiness to change was evaluated as a predictor of cannabis use
outcomes using two questionnaires.
The main finding was that cannabis use was not associated with psychotic
outcomes but was related to other illicit drug use. With regards to reasons,
patients chose enhancement and social motives as most important for their
cannabis use providing support for the ‘alleviation of dysphoria’ model.
Preliminary analysis showed no clear pattern of association between readiness to
change and cannabis use outcome. Utility of two readiness to change measures
for use with patients with psychosis was not validated.
These findings add to the small evidence base that cannabis use is not
associated with prognostic outcomes in psychosis. No evidence for the self medication hypothesis was observed. Readiness to change was not associated
with cannabis use outcomes signifying the need for using validated measures to
assess motivation in psychotic populations.","abstract_html":"There is ample evidence that patients with psychosis are more likely to<br/>use illicit substances than the general population, with cannabis being the most<br/>popular. Research has also shown that cannabis use is associated with poor<br/>prognostic outcomes in patients with an established psychotic disorder. It is<br/>important to understand the reasons patients with psychosis endorse for their<br/>cannabis use and findings so far point towards an ‘alleviation of dysphoria’ model<br/>rather than the ‘self-medication’ hypothesis. It is not known how the level of<br/>motivation to change cannabis use can affect patients’ actual use. Lack of<br/>validated readiness to change questionnaires for use with psychotic populations<br/>makes it essential to develop and validate such measures.<br/>The aim of this thesis was to evaluate the reasons for cannabis use and its<br/>effects on psychotic outcomes in a patient cohort with first-episode psychosis.<br/>The association between cannabis use and other illicit drug use was also<br/>investigated. Readiness to change was evaluated as a predictor of cannabis use<br/>outcomes using two questionnaires.<br/>The main finding was that cannabis use was not associated with psychotic<br/>outcomes but was related to other illicit drug use. With regards to reasons,<br/>patients chose enhancement and social motives as most important for their<br/>cannabis use providing support for the ‘alleviation of dysphoria’ model.<br/>Preliminary analysis showed no clear pattern of association between readiness to<br/>change and cannabis use outcome. Utility of two readiness to change measures<br/>for use with patients with psychosis was not validated.<br/>These findings add to the small evidence base that cannabis use is not<br/>associated with prognostic outcomes in psychosis. No evidence for the self medication hypothesis was observed. Readiness to change was not associated<br/>with cannabis use outcomes signifying the need for using validated measures to<br/>assess motivation in psychotic populations.","abstract_has_math":false,"creators":["Kolliakou, Anna"],"institution":"King's College London","degree_name":"Doctor of Philosophy","degree_level":"Doctoral Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Ismail, Khalida"],"committee_chairs":[],"committee_members":[],"year":2013,"date_issued":"2013-7","date_published":"2013-7","updated_at":"2026-07-24T02:44:40Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:kclpure.kcl.ac.uk:studenttheses/9d70beb1-9b58-4143-9bc6-87065b64866b"],"render_values":[{"text":"oai:kclpure.kcl.ac.uk:studenttheses/9d70beb1-9b58-4143-9bc6-87065b64866b","href":null,"code":true}]}]},"links":{"outbound_url":"https://kclpure.kcl.ac.uk/portal/en/studentTheses/9d70beb1-9b58-4143-9bc6-87065b64866b","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Ismail, Khalida"]},{"key":"dc:creator","label":"Author","values":["Kolliakou, Anna"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2013-7"]},{"key":"dc:date.issued","label":"Date","values":["2013-7"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Psychological Medicine"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["King's College London"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://kclpure.kcl.ac.uk/portal/en/studentTheses/9d70beb1-9b58-4143-9bc6-87065b64866b"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral Thesis"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:kclpure.kcl.ac.uk:studenttheses/9d70beb1-9b58-4143-9bc6-87065b64866b","https://kclpure.kcl.ac.uk/portal/en/studentTheses/9d70beb1-9b58-4143-9bc6-87065b64866b"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://kclpure.kcl.ac.uk/portal/files/12927598/Studentthesis-Anna_Kolliakou_2013.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["There is ample evidence that patients with psychosis are more likely to
use illicit substances than the general population, with cannabis being the most
popular. Research has also shown that cannabis use is associated with poor
prognostic outcomes in patients with an established psychotic disorder. It is
important to understand the reasons patients with psychosis endorse for their
cannabis use and findings so far point towards an ‘alleviation of dysphoria’ model
rather than the ‘self-medication’ hypothesis. It is not known how the level of
motivation to change cannabis use can affect patients’ actual use. Lack of
validated readiness to change questionnaires for use with psychotic populations
makes it essential to develop and validate such measures.
The aim of this thesis was to evaluate the reasons for cannabis use and its
effects on psychotic outcomes in a patient cohort with first-episode psychosis.
The association between cannabis use and other illicit drug use was also
investigated. Readiness to change was evaluated as a predictor of cannabis use
outcomes using two questionnaires.
The main finding was that cannabis use was not associated with psychotic
outcomes but was related to other illicit drug use. With regards to reasons,
patients chose enhancement and social motives as most important for their
cannabis use providing support for the ‘alleviation of dysphoria’ model.
Preliminary analysis showed no clear pattern of association between readiness to
change and cannabis use outcome. Utility of two readiness to change measures
for use with patients with psychosis was not validated.
These findings add to the small evidence base that cannabis use is not
associated with prognostic outcomes in psychosis. No evidence for the self medication hypothesis was observed. Readiness to change was not associated
with cannabis use outcomes signifying the need for using validated measures to
assess motivation in psychotic populations."]},{"key":"dc:title","label":"Title","values":["Patterns of cannabis use in first-episode psychosis"]}]}],"canonical_facts":{"dc:contributor.advisor":["Ismail, Khalida"],"dc:creator":["Kolliakou, Anna"],"dc:date":["2013-7"],"dc:date.issued":["2013-7"],"dc:description.abstract":["There is ample evidence that patients with psychosis are more likely to
use illicit substances than the general population, with cannabis being the most
popular. Research has also shown that cannabis use is associated with poor
prognostic outcomes in patients with an established psychotic disorder. It is
important to understand the reasons patients with psychosis endorse for their
cannabis use and findings so far point towards an ‘alleviation of dysphoria’ model
rather than the ‘self-medication’ hypothesis. It is not known how the level of
motivation to change cannabis use can affect patients’ actual use. Lack of
validated readiness to change questionnaires for use with psychotic populations
makes it essential to develop and validate such measures.
The aim of this thesis was to evaluate the reasons for cannabis use and its
effects on psychotic outcomes in a patient cohort with first-episode psychosis.
The association between cannabis use and other illicit drug use was also
investigated. Readiness to change was evaluated as a predictor of cannabis use
outcomes using two questionnaires.
The main finding was that cannabis use was not associated with psychotic
outcomes but was related to other illicit drug use. With regards to reasons,
patients chose enhancement and social motives as most important for their
cannabis use providing support for the ‘alleviation of dysphoria’ model.
Preliminary analysis showed no clear pattern of association between readiness to
change and cannabis use outcome. Utility of two readiness to change measures
for use with patients with psychosis was not validated.
These findings add to the small evidence base that cannabis use is not
associated with prognostic outcomes in psychosis. No evidence for the self medication hypothesis was observed. Readiness to change was not associated
with cannabis use outcomes signifying the need for using validated measures to
assess motivation in psychotic populations."],"dc:identifier":["oai:kclpure.kcl.ac.uk:studenttheses/9d70beb1-9b58-4143-9bc6-87065b64866b","https://kclpure.kcl.ac.uk/portal/en/studentTheses/9d70beb1-9b58-4143-9bc6-87065b64866b"],"dc:identifier.uri":["https://kclpure.kcl.ac.uk/portal/files/12927598/Studentthesis-Anna_Kolliakou_2013.pdf"],"dc:language":["eng"],"dc:publisher.department":["Psychological Medicine"],"dc:publisher.institution":["King's College London"],"dc:relation.isreferencedby":["https://kclpure.kcl.ac.uk/portal/en/studentTheses/9d70beb1-9b58-4143-9bc6-87065b64866b"],"dc:title":["Patterns of cannabis use in first-episode psychosis"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral Thesis"],"dc:type.qualificationname":["Doctor of Philosophy"]},"updated_at":"2026-07-24T02:44:40Z"}