Suicide attempts and opioid dependence are important clinical issues, as both are associated with a high degree of psychiatric morbidity and elevated risk of mortality. Research has identified a number of risk factors for suicide attempts among the general population, and to a lesser extent, among heroin users. Due to a lack of case-control studies, however, it is still not known to what extent opioid dependence per se is a risk factor for suicide attempts. This thesis comprised the first study to directly examine whether opioid dependence is a unique risk factor of suicide attempts. This thesis examined suicide attempts, associated risk factors, and related comorbidity among an opioid-dependent case group and a non-opioid-dependent control group. A structured interview was used to collect data from 726 opioid-dependent cases and 399 non-opioid-dependent controls. This thesis identified a number of important findings. Firstly, although opioid-dependent individuals were more likely to report lifetime suicide attempts compared to controls, the risk factors were largely the same for both groups. It appeared that opioid-dependent individuals were characterised by a higher likelihood of the same risk factors for suicide attempts, rather than having different risks. Cases appeared to be at increased risk of suicide attempts because of increased levels of multiple risk factors. Secondly, borderline personality disorder (BPD) and impulsivity were identified as important risk markers for suicidal behaviour, especially among opioid-dependent individuals. The study concluded that the treatment of BPD should be prioritised among this group. Third, self-mutilation was identified as a clinically significant problem in its own right, however, when combined with a history of attempted suicide, the psychological dysfunction observed was found to be very high. Fourth, non-fatal opioid overdose and suicide attempts were found to be distinct behaviours. The risk factors for each were completely different. While drug-related risks were associated with non-fatal overdose, the risk markers for suicide attempts were related to the presence of psychological disorders. This thesis has highlighted important areas of concern for clinical interventions as well as for future research to explore. Considering this is the first study of its kind, future research should focus on its replication.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 167-180). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 167-180). Also available on the Internet.

Thesis (M.S.)--University of Missouri--Columbia, 2000. / Typescript. Includes bibliographical references (leaves [32]-35). Also available on the Internet.

Suicide attempts and opioid dependence are important clinical issues, as both are associated with a high degree of psychiatric morbidity and elevated risk of mortality. Research has identified a number of risk factors for suicide attempts among the general population, and to a lesser extent, among heroin users. Due to a lack of case-control studies, however, it is still not known to what extent opioid dependence per se is a risk factor for suicide attempts. This thesis comprised the first study to directly examine whether opioid dependence is a unique risk factor of suicide attempts. This thesis examined suicide attempts, associated risk factors, and related comorbidity among an opioid-dependent case group and a non-opioid-dependent control group. A structured interview was used to collect data from 726 opioid-dependent cases and 399 non-opioid-dependent controls. This thesis identified a number of important findings. Firstly, although opioid-dependent individuals were more likely to report lifetime suicide attempts compared to controls, the risk factors were largely the same for both groups. It appeared that opioid-dependent individuals were characterised by a higher likelihood of the same risk factors for suicide attempts, rather than having different risks. Cases appeared to be at increased risk of suicide attempts because of increased levels of multiple risk factors. Secondly, borderline personality disorder (BPD) and impulsivity were identified as important risk markers for suicidal behaviour, especially among opioid-dependent individuals. The study concluded that the treatment of BPD should be prioritised among this group. Third, self-mutilation was identified as a clinically significant problem in its own right, however, when combined with a history of attempted suicide, the psychological dysfunction observed was found to be very high. Fourth, non-fatal opioid overdose and suicide attempts were found to be distinct behaviours. The risk factors for each were completely different. While drug-related risks were associated with non-fatal overdose, the risk markers for suicide attempts were related to the presence of psychological disorders. This thesis has highlighted important areas of concern for clinical interventions as well as for future research to explore. Considering this is the first study of its kind, future research should focus on its replication.

A question that has plagued New Zealand botanists for many years is the occurrence of the divaricate growth form in several different plant families, and what selection pressure could have led to such parallel evolution. One prominent theory is that the divaricate habit is an adaptation to climatic extremes. This study aims to test if the 'self-shading' growth form of divaricates protects their internal leaves from photoinhibition under physiological drought and high irradiance. By being able to forego the costs of maintaining photoprotective mechanisms, they should have greater carbon gain than their non-divaricate congeners under these conditions. To test if divaricates are protected from the detrimental effects of photoinhibition, the water potentials, pigment and vitamin E concentrations, and photosynthetic rates of two divaricates species in their natural habitat were measured. Additionally, these parameters were recorded for the same divaricate species and their non-divaricate congeners under glasshouse conditions. In the field there were clear differences in several key parameters between divaricates under different levels of irradiance and water availability, and in most cases there was clear evidence of photoinbition. In the glasshouse, the maximum photosynthetic rates were significantly higher in divaricate leaves than in non-divaricate leaves, but there were no clear differences in the avoidance of photoinhibition between divaricates and non-divaricates. Interestingly, more pronounced responses to the different treatments were observed between genera than between the growth forms in the field and glasshouse experiments. The presence of photoinhibition and photoprotective mechanisms in divaricate leaves does not support the theory that the divaricate habit evolved as a physiological response to extreme climate conditions. The absence of a strong difference in the amount of photoinhibition between divariacte and non-divaricate congeners mean that high irradiance and drought stress are unlikely to have been a key factor in the evolution of the divaricate habit. That the within genus physiologies are more similar than within the growth forms would indicate that the divaricate habit possibly evolved after the evolution of the physiological responses of the genera.

Thesis (Ph. D.) -- McMaster University, 1997. / Includes bibliographical references (leaves 91-102). Also available via World Wide Web.

Thesis (M. Med. Sc.)--University of Hong Kong, 2005. / Also available in print.

Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 101-106).

Thesis (D.P.H.)--University of Michigan, 1991. / Includes bibliographical references (p. 62). Also issued in print.