Despite a prevailing paradigm that emphasizes an interaction
of vulnerability and stress to account for the etiology of
schizophrenia, diathesis—stress models of subsequent course and
outcome of this disorder are rare. Even the simpler stress—
process model, where the influence of stressors is mediated by
supportive social relationships, has received little attention
in studies of the course of schizophrenia.
The objective of this study was to assess the following
components of a diathesis—stress model as they predict the five-year
outcome of first-episode schizophrenia: (1) stressful life
events; (2) supportive social relationships; (3) brain lateral
ventricle size; and (4) smooth pursuit eye movements.
As part of the Greater Vancouver M.A.P. Project, we recruited
first-episode DSM-III schizophrenia and affective psychosis
patients. At intake to the study, their social relationships,
smooth pursuit eye movement function, and brain ventricle size
were assessed. Life events in the previous year were measured
at intake; events over the following 18 months were assessed in
two later interviews. Five years later we assessed outcome,
using a global rating of social and occupational functioning.
Descriptive results showed substantial variability within the
schizophrenia group at intake and outcome. The trajectory of
adaptive functioning over time was remarkably similar for the
schizophrenic and affective psychosis groups. Of the four hypothesized predictors, only social relationships were
associated (p=.O3) with five—year outcome. The number of life
events was not associated with five—year outcome, nor was either
of the biological risk factors. As a result, the predictor
variables could not be combined in either a stress—process model
or a vulnerability—stress model of the course of schizophrenia.
That social relationship variables are associated with five-year
outcome supports earlier findings regarding 18-month
outcome, including the differing predictive roles for family and
nonfamily relationships. The absence of hypothesized results
for the life events data probably indicates that too much time
had passed between outcome and the events as measured. Finally,
that brain ventricle size and eye-movement dysfunction predict
18-month but not five—year outcome may indicate that impairment
due to biological factors is expressed only in the early stages
of schizophrenia.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/6866 |
| Date | 05 1900 |
| Creators | Erickson, David Harry |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Relation | UBC Retrospective Theses Digitization Project [http://www.library.ubc.ca/archives/retro_theses/] |
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