Browsing by Author "Taylor, Valerie H"

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    Decision-making about antidepressant medication use in pregnancy: a comparison between women making the decision in the preconception period versus in pregnancy
    (2020-02-07) Barker, Lucy C; Dennis, Cindy-Lee; Hussain-Shamsy, Neesha; Stewart, Donna E; Grigoriadis, Sophie; Metcalfe, Kelly; Oberlander, Tim F; Schram, Carrie; Taylor, Valerie H; Vigod, Simone N
    Abstract Background Decisions about antidepressant use in pregnancy are complex. Little is known about how pregnancy-planning and already pregnant women making these decisions differ. Methods In 95 Canadian women having difficulty deciding whether to take antidepressants in pregnancy, we compared sociodemographic factors, clinical characteristics, and treatment intent between women planning pregnancy (preconception women) and currently-pregnant women. Results About 90% of preconception women (n = 55) were married or cohabitating and university-educated, and over 60% had an annual income of > 80,000 CAD/year; this was not different from currently-pregnant women (n = 40). Almost all women had previously used antidepressants, but preconception women were more likely to report current use (85.5% vs. 45.0%). They were more likely to have high decisional conflict (83.6% vs. 60.0%) and less likely to be under the care of a psychiatrist (29.1% vs. 52.5%). Preconception women were more likely than pregnant women to report the intent to use antidepressants (60% vs. 32.5%, odds ratio 3.11, 95% confidence interval 1.33–7.32); this was partially explained by between-group differences in current antidepressant use. Conclusions Preconception women were more likely than pregnant women to intend to use antidepressants in pregnancy, in part because more of them were already using this treatment. Strategies to enhance support for decision-making about antidepressant medication use in pregnancy may need to be tailored differently for pregnancy-planning and already pregnant women.
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    Effect of Bacterial Species Associated with Major Depressive Disorder on Emotionality Behaviors, Microbiome Structure, and Metabolism in Gnotobiotic Mouse Models
    (2021-08-17) Cooke, Noah C.A.; McCoy, Kathy D; Taylor, Valerie H; Hirota, Simon; McGirr, Alexander; Sharkey, Keith A; Savchenko, Alexei
    Major depressive disorder (MDD) is a prevalent disease, and antidepressants lack efficacy in many patients, motivating investigation for new therapeutic modalities. Altered microbiome composition and metabolism have been implicated in MDD, but the specific species and metabolites involved, and their mechanisms of effect, remain elusive. We set out to test whether two bacterial species correlated with MDD alter emotionality-related behaviors in stress-naïve and chronic stress-exposed mice, when added to the stable defined moderately diverse mouse microbiome 2 (sDMDMm2) consortium. We hypothesized that Lachnospiraceae bacterium would increase, and Faecalibacterium prausnitzii would decrease, these behaviors in both conditions. Further, we hypothesized that these behavioural effects would coincide with effects on microbiome composition and metabolism. To assess emotionality-like behavior, we established a gnotobiotic behavioral system comprised of five tests and the chronic variable stress (CVS) model for studying depression. L. bacterium did not alter depressive and anxiety-like behaviors in the stress-naïve condition. In the CVS condition, an increase in anxiety-like behavior was seen in one assay, the elevated plus maze test, in one preliminary experimental replicate. Illumina 16S V4 amplicon sequencing revealed that L. bacterium significantly altered microbiome composition. Hydrophilic interaction liquid chromatography with mass spectrometry (HILIC-MS/MS) also revealed a significant effect of L. bacterium on microbiome and serum metabolism. This thesis offers a novel methodological approach to investigate causal relationships between bacterial species and emotionality-related behaviors, and to identify microbial candidates for microbiome-targeted therapies for MDD.Keywords: microbiome, Lachnospiriceae bacterium, Major Depressive Disorder, Metabolism.
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    Identifying contexts and mechanisms in multiple behavior change interventions affecting smoking cessation success: a rapid realist review
    (2020-06-12) Minian, Nadia; Corrin, Tricia; Lingam, Mathangee; deRuiter, Wayne K; Rodak, Terri; Taylor, Valerie H; Manson, Heather; Dragonetti, Rosa; Zawertailo, Laurie; Melamed, Osnat C; Hahn, Margaret; Selby, Peter
    Abstract Background Smoking continues to be a leading cause of preventable chronic disease-related morbidity and mortality, excess healthcare expenditure, and lost work productivity. Tobacco users are disproportionately more likely to be engaging in other modifiable risk behaviours such as excess alcohol consumption, physical inactivity, and poor diet. While hundreds of interventions addressing the clustering of smoking and other modifiable risk behaviours have been conducted worldwide, there is insufficient information available about the context and mechanisms in these interventions that promote successful smoking cessation. The aim of this rapid realist review was to identify possible contexts and mechanisms used in multiple health behaviour change interventions (targeting tobacco and two or more additional risk behaviours) that are associated with improving smoking cessation outcome. Methods This realist review method incorporated the following steps: (1) clarifying the scope, (2) searching for relevant evidence, (3) relevance confirmation, data extraction, and quality assessment, (4) data analysis and synthesis. Results Of the 20,423 articles screened, 138 articles were included in this realist review. Following Michie et al.’s behavior change model (the COM-B model), capability, opportunity, and motivation were used to identify the mechanisms of behaviour change. Universally, increasing opportunities (i.e. factors that lie outside the individual that prompt the behaviour or make it possible) for participants to engage in healthy behaviours was associated with smoking cessation success. However, increasing participant’s capability or motivation to make a behaviour change was only successful within certain contexts. Conclusion In order to address multiple health behaviours and assist individuals in quitting smoking, public health promotion interventions need to shift away from ‘individualistic epidemiology’ and invest resources into modifying factors that are external from the individual (i.e. creating a supportive environment). Trial registration PROSPERO registration number: CRD42017064430