Page 3 - PhD GT

ABSTRACT
The aim of this thesis is to investigate the nature of change in substance dependence with particular reference to the course of its decline. It is argued that theories of dependence have concentrated on the development of the condition while less attention has been paid to the course of its decline. Furthermore the way in which dependence is measured does not allow for the measurement of the phenomenon during periods of abstinence, thus implying that it does not continue when use of the substance has ceased. A psychological theory of substance dependence has generated a measurement instrument (LDQ) which accounts for dependence across the spectrum of severity and patterns of use including abstinence and this instrument is used to chart the course of change and decline.
The psychometric properties of the LDQ are further examined to establish the sensitivity of the measure for the purpose of the present study. Correlates of change in dependence are examined and two measurement instruments, one for impaired control and one for coping, are adapted for the purpose of charting the course of change in dependence in both heroin users and alcohol drinkers. These measures, together with measures of psychological and social functioning, are used to investigate the predictors of change in dependence.
It is found to be the case that dependence declines and such decline is accompanied by improvement on other measures of functioning; the predictors of decline in dependence remain elusive given the measures used in the study. Evidence is produced for the role of cognitive and behavioural coping strategies in change, though the nature and direction of the relationships remain unclear. The inter-relationships between use and dependence are identified and again the direction and influence of such relationships require further research.
The value of the measurement of dependence is proposed for the purpose of improved understanding which underlies the development of effective treatment modalities and meaningful outcome evaluation.
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