Neuroleptic dysphoria
Subtitle: iological and applied aspects of subjective responses to antipsychotic drugs.
Published: 2004
Language: eng
Number of pages: 146
Description: Conclusions. Drug-induced alterations in dopamine function are largely responsible for the occurrence of dysphoria associated with neuroleptic treatment; and the degree of vulnerability to dysphoria could be linked to the variations in endogenous dopaminergic activity. Altering the characteristics of dopaminergic blockade, or dopamine's interactions with other neurotransmitters (eg., serotonin and norepinephrine) seem to modify the nature of subjective responses, expanding the scope for developing novel therapeutic agents.Results. In the first study, catecholamine depletion was associated with emergence of dysphoric responses among all the subjects; and dysphoria was identified as an uneasy awareness of a loss of ability to experience pleasure, along with changes in arousal, mood, thinking, and motivation. The onset and severity of dysphoria were inversely related to striatal D 2 binding ratio [r = -0.82, p &lt; 0.01]; a sub-group of subjects with significantly lower binding ratios showed earlier and severe dysphoric response compared to those with higher binding ratios at the baseline [F = 7.63,  p &lt; 0.02]. In the second study, the severity of dysphoria was significantly lower among subjects receiving novel antipsychotic drugs [ F = 3.85, p &lt; 0.05]; and in the third study, a switch from conventional to novel antipsychotic drug lowered the rate and severity of dysphoria, and the improved tolerability was sustained during the follow up period with a concomitant improvement in treatment-adherence and quality of life.Background. Neuroleptic dysphoria is a subtle and under-recognized side effect of conventional antipsychotic drugs that has been linked to a variety of adverse clinical consequences.Objectives. The purpose of the project was to (a) investigate the role of dopaminergic blockade in the origin of neuroleptic dysphoria, and (b) examine the changes in the prevalence and severity of dysphoria after switching to antipsychotic drugs with atypical receptor blocking profile.The second and third studies examined a hypothesis that novel antipsychotic drugs compared to conventional dopamine blocking agents, cause significantly lower dysphoric responses. In the second study, comparable groups of individuals with schizophrenia treated with conventional [n = 44] or novel [n = 186] antipsychotic drugs were cross-sectionally evaluated to determine the relative prevalence of dysphoria in both groups. In the third study, a cohort of 150 subjects treated for schizophrenia were switched from neuroleptics to novel antipsychotic drugs and prospectively evaluated, monitoring changes in their subjective responses and treatment-adherence over a period of 2--5 years.Methods. The thesis is based on three studies. The first study tested a hypothesis that impaired dopamine function leads to dysphoric responses. In a clinical experiment, alpha-methyl paratyrosine [AMPT], a catecholamine depleting drug, was administered to a group of drug-free schizophrenic patients [n = 13] over a 48 hr. period. Patients' subjective responses were monitored with self-administered rating scales, and changes in striatal dopamine D 2 binding ratios were quantified through performing concurrent single photon emission computed tomographic [SPECT] scans.
Notes: Adviser:  Awad G. Awad.

Thesis (Ph.D.)--University of Toronto, 2004.

Electronic version licensed for access by U. of T. users.

Source: Dissertation Abstracts International, Volume: 65-05, Section: B, page: 2364.