Class of 2013 Abstract / Specific Aims: To describe the incidence of hyponatremia in patients using SSRIs and to assess how often health care professionals obtain electrolyte panels after SSRI initiation. Also, to identify the most recent sodium level in patients and to compare sodium levels in a patient group using an SSRI and a control group not using an SSRI. Subjects: Patients who received care at a large multi-center ambulatory care clinic between January 1st, 2008 and December 31st, 2011. Methods: An electronic medical record database was used to identify potential patients through medication records reflecting SSRI use or diagnosis of low back pain, obesity, pruritis, rash, or fibromyalgia. The following data was collected: patient gender, age, weight, height, use/non-use of SSRI, plasma sodium level, and documented past hyponatremia diagnosis. Plasma sodium levels and hyponatremia incidence were compared from the SSRI group to the non-SSRI group. In addition, the SSRI group was analyzed for incidence of documented hyponatremia. Monitoring of sodium levels after SSRI initiation was also investigated. Main Results: Overall, 500 charts were reviewed. After inclusion and exclusion criteria were applied, 118 patients were included in the study (38 in the SSRI group, 80 in the control group). The incidence of hyponatremia in the SSRI group and control group was 2.63% and 1.25% respectively. There was no significant difference between groups (p=0.542). Sodium levels were monitored 19.2% of the time after SSRI initiation. Conclusion: The incidence of hyponatremia was similar between groups. Physicians are not adequately monitoring for hyponatremia after SSRI initiation.

Meperidine has been shown to have potent binding affinity for serotonin transporters (SERT) (Ki = 41 nM) and be an inhibitor of serotonin reuptake. Based upon these pharmacological results meperidine has been identified as a lead compound for the development of a novel class of serotonin-selective reuptake inhibitors (SSRIs). A variety of potent analogues of meperidine have been synthesized and evaluated in vitro as potential ligands for the serotonin transporter. Substitutions have been made on the aryl ring, the ester moiety and the piperidine nitrogen of meperidine. Potent analogues of the aryl substituted series that included 4-iodophenyl, 2-naphthyl, 3,4-dichlorophenyl and 4-biphenyl meperidine derivatives were synthesized and chosen for further optimization of the benzyl ester analogues. Benzyl ester analogues included 4-nitro, 4-methoxyl and 3,4-dichloro benzyl analogues and exhibited high potency for serotonin transporters and high selectivity over the dopamine transporter (DAT) and the norepinephrine transporter (NET). Also the N-demethylated analogues improve the binding affinity and selectivity for serotonin transporter. The analogue 4- (carboxymethoxybenzyl)-4-(4-iodophenyl) piperidine (69f), was found the most potent (Ki=0.6 nM) and selective ligand for serotonin transporter (DAT/SERT >4500; NET/SERT >4500) for the series and has been advanced to in vivo evaluation.

A defined group of medical records was surveyed for patients who showed onset of major depression with melancholic features while taking an antidepressant medication. Nine cases resulted. In all the antidepressants being taken while melancholia began were SSRIs and the melancholic depression remitted rapidly with the first treatment given, bupropion in five males, nortriptyline with triiodothyronine in two females, and ECT in one male and one female. This suggests that patients who take SSRIs and are melancholic respond well to bupropion, nortriptyline, or ECT. These observations complement reports of low responsivity of melancholic depression to SSRIs and distinctions between melancholic and nonmelancholic depressions.

Evidence suggests that selective serotonin reuptake inhibitors (SSRIs, a class of antidepressant medications) may contribute to increased breast cancer risk by stimulating the secretion of prolactin, a potential tumour promoter. The main objective of this study was to determine breast cancer risk associated with the duration, dosage and timing of SSRI use among women, with control for a limited set of confounders. This thesis project, conducted within the context of a population-based two-stage case-control study, consisted of a record linkage study utilizing three Saskatchewan health services databases. Cases included 1,273 women with primary breast cancer diagnosed between January 1, 2003 and December 31, 2005, and controls consisted of 12,730 subjects randomly selected from the province’s population registry. Data on SSRI use was compiled from the Saskatchewan prescription drug plan database. Information on a limited set of established risk factors for breast cancer that may confound this relationship was ascertained from the population registry and the prescription database. Cases and controls were similar in terms of age, total number of consecutive years eligible for prescription coverage and indicators of socioeconomic status. Compared to controls, cases were more likely to be married and to have used hormone therapy and/or oral contraceptives. Compared to nonusers, results indicated that the use of SSRIs for three or more years (as estimated by having filled 36 or more prescriptions for all SSRIs combined during the main exposure window more than two years prior to index date) was not associated with an increased risk of breast cancer (OR= 1.08, 95% CI: 0.74-1.58), controlling for age, marital status, oral contraceptive and hormone therapy use. In addition, no suggestion of increased risk was detected for long-term exposures to individual SSRIs (24 or more prescriptions filled during the main exposure window) and in relation to total combined SSRI use 2-7 years and more than seven years prior to index date. However, these risk estimates may have been affected by potential sources of information bias and confounding. In summary, these results do not provide evidence to suggest that the risk of breast cancer is increased with the use of SSRIs. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2008-01-08 13:51:38.74

The placebo effect, a beneficial effect attributable to a treatment containing no specific properties for the condition being treated, has been demonstrated in a variety of medical conditions. This thesis includes four studies aimed at increasing our knowledge on the neurobiology of placebo. Study I, a review of the placebo neuroimaging literature, suggested that the anterior cingulate cortex (ACC) may be a common site of action for placebo responses. However, because placebo neuroimaging studies in clinical disorders are largely lacking, the clinical relevance of this needs further clarification. The subsequent three empirical studies were thus designed from a clinical perspective. Using positron emission tomography (PET) these studies investigated the underlying neurobiology of sustained placebo responses in patients with social anxiety disorder (SAD), a disabling psychiatric condition that nonetheless may be mitigated by placebo interventions. Study II demonstrated that serotonergic gene polymorphisms affect anxiety-induced neural activity and the resultant placebo phenotype. In particular, anxiety reduction resulting from placebo treatment was tied to the attenuating effects of the TPH2 G-703T polymorphism on amygdala activity. Study III further compared the neural response profile of placebo with selective serotonin reuptake inhibitors (SSRIs), i.e the first-line pharmacological treatment for SAD. A similar anxiety reduction was noted in responders of both treatments. PET-data further revealed that placebo and SSRI responders had similar decreases of the neural response in amygdala subregions including the left basomedial/basolateral (BM/BLA) and the right ventrolateral (VLA) sections. To clarify whether successful placebo and SSRI treatments operate via similar or distinct neuromodulatory pathways, study IV focused on the connectivity patterns between the amygdala and prefrontal cortex that may be crucial for normal emotion regulation. In responders of both treatment modalities, the left amygdala (BM/BLA) exhibited negative coupling with the dorsolateral prefrontal cortex and the rostral ACC as well as a shared positive coupling with the dorsal ACC. This may represent shared treatment mechanisms involving improved emotion regulation and decreased rumination. This thesis constitutes a first step towards better understanding of the neurobiology of placebo in the treatment of anxiety, including the neural mechanisms that unite and segregate placebo and SSRI treatment.

The serotonergic system is involved in a broad range of functions in both vertebrates and invertebrates and is highly conserved across taxa. Serotonin is an important monoamine acting in the brains of humans and animals, and has large and varying influences on many aspects of an individual’s life. For example, in humans, serotonin modulates feelings of happiness and in fruit flies, higher levels of serotonin increase aggression. In humans, an abnormal serotonergic system can result in health issues, such as depression and obsessive compulsive disorders, for which medications have been developed, including selective serotonin reuptake inhibitors (SSRI). Because the serotonin system has a large influence on human health, understanding how it functions is of great interest to researchers. Using comparative studies to explore differences in the serotonin system across taxa can provide insight into the mechanistic details of the system. To investigate if the serotonin system is comparable between vertebrates and invertebrates, a literature study with particular focus on receptors and proteins involved was performed. In addition, this report takes part in an experimental study investigating the effect of the SSRI fluoxetine in Mediterranean field crickets.  Fluoxetine reduced exploration propensity of crickets, which was reversed, compared to what was anticipated and compared to effects seen in vertebrates. The literature review suggests that serotonin receptors are quite similar, but that proteins differ more when comparing vertebrates and invertebrates. This offers a likely explanation as to why results of studies on these different groups of animals may differ.

No description available.

10-15% of women take antidepressants during pregnancy. Selective serotonin reuptake inhibitors (SSRIs) are most commonly used for perinatal depression. Perinatal exposure to SSRIs has been shown to disrupt the development of serotonergic signaling pathways in the central nervous system (CNS); however, the effects on the developing enteric nervous system (ENS) remain relatively unexplored. We hypothesized that early life exposure to SSRIs would influence the structural development of the gastrointestinal (GI) tract. We further hypothesized that these structural changes could lead to clinically relevant functional outcomes, such as modifications in susceptibility to inflammation and altered GI motility. Female Wistar rats were given the SSRI, fluoxetine, or vehicle from 2 weeks prior to mating through gestation until weaning. At postnatal day 1 (P1), postnatal day 21 (P21; weaning) and 6 months of age (P6 months) intestines were harvested to assess for structural changes. At P6M, intestines were collected to assess motility in vitro and subsets of the offspring were treated with dextran sulfate sodium (DSS) to assess susceptibility to colitis. At P1, there was a significant decrease in serotonergic neurons in the female colon. At P21, there was a significant increase in serotonergic neurons of both sexes in the colon. At P6M, there was a significant increase in the frequency and velocity of long-distance contractions in the colon when both sexes were combined and an increase in ZO-1 in male colon. In conclusion, SSRI exposure in utero appears to have structural and functional consequences on the developing ENS in the SSRI exposed offspring. The structural consequences are seen in both sexes at P21 and although the structural changes to the ENS resolve by 6 months, motility in the colon continues to be significantly altered. There were no significant differences in chemical colitis, however, we did see difference of quantitative mRNA cytokines, chemokines and extracellular matrix components which may suggest differences in mucosal immune response. The mechanisms by which these changes occur remain to be explored. / Thesis / Master of Science (MSc)

Major depressive disorder (MDD) is considered the current leading cause of disability worldwide (Friedrich, 2017), yet the recovery process in MDD, including neurobiological underpinnings, clinical features and optimal approaches to treatment remains ambiguous. Current definitions of recovery are disputed and involve measures considered subjective in nature, such as thresholds for questionnaires and clinical interviews of symptoms and their duration (De Zwart and Jeronimus, 2019; Fava et al., 2007; Keller, 2003, 2004). Symptom-based measures, although informative of clinical presentation, are not informative of neurobiological underpinnings that may persist even when symptoms are reduced. Indeed, even after treatment, persistent residual symptoms, impairments in quality of life, and vulnerabilities for future return to more severe psychopathology persist (Gotlib and Hammen, 2008; IsHak et al., 2011; Judd et al., 1998a; Kennedy et al., 2004; Kennedy and Foy, 2005; Kennedy and Paykel, 2004). Without assessment of neural mechanisms of recovery in MDD, efforts toward developing novel treatment approaches that are able to address neural processes of illness and to provide sustained remission are slowed. The following collection of studies provide neural and clinical insights into MDD recovery and relate findings to potential treatment approaches that are optimized to individual differences in symptoms and neural functioning and able to address neural vulnerabilities to provide sustained remission. In pursuit of individualized treatment selection in MDD, study one involved a meta-analysis of prior prognostic fMRI studies of response to cognitive behavioral therapy (CBT) or a selective serotonin reuptake inhibitor (SSRI) in MDD. Study one also reported on the application of resulting meta-analytic regions (subgenual and perigenual anterior cingulate cortex) in a confirmatory MDD sample. Although regions showed some predictive potential in the confirmatory sample, when predicting SSRI response, effects were inconsistent with prior studies, suggesting methodological confounds may hinder ready translation. In an assessment of the course of MDD, the second study documented depression symptoms and quality of life across 9-14 years after acute treatment (CBT or SSRI) and found that persistent residual depression symptoms and quality of life deficits were common. In light of the normality of chronic symptoms and impairment, the third study evaluated neural features of treatment (CBT) resistance in MDD within the context of neural mechanisms of change. The third study found a vermis-centered cerebellar cluster that was unresponsive to CBT, whereas prefrontal and parietal cortical regions were responsive, providing support of prior theories that CBT directly affects cognitive control and cortical regulatory processes in contrast to salience-driven subcortical functioning (Clark and Beck, 2010; DeRubeis et al., 2008; Frewen et al., 2008; Mayberg, 2003). In consideration of findings, clinical recommendations that pertain to treating residual symptoms and associated neural features toward asymptomatic remission are provided. Future research directions are also provided regarding neuroscience informed precision medicine, current therapy and medication practices, and the larger picture of MDD chronicity broadly. / Doctor of Philosophy / Major depressive disorder (MDD) is considered the leading cause of disability worldwide (Friedrich, 2017), yet there are many aspects of MDD recovery that are unclear such as neural and clinical features and optimal treatment approaches. Current definitions of recovery involve questionnaires and interviews, which may not accurately represent all aspects of recovery (De Zwart and Jeronimus, 2019; Fava et al., 2007; Keller, 2003, 2004). For example, they do not assess neural or biological features of recovery that may continue even if symptoms improve. Indeed, even after treatment, often some minimal depression symptoms, impairments in quality of life, and risks for future more severe symptoms continue (Gotlib and Hammen, 2008; IsHak et al., 2011; Judd et al., 1998a; Kennedy et al., 2004; Kennedy and Foy, 2005; Kennedy and Paykel, 2004). Without assessing neural features of MDD and recovery, developing treatments that can address illness- related neural features and provide sustained recovery are slowed. The following studies report on neural and clinical features of MDD recovery to approach treatment and sustained recovery with consideration of individual differences in symptoms and neural functioning. Pursuing neuroimaging measures of individual differences to inform treatment selection, study one involved a statistical review of prior neuroimaging prediction studies of MDD treatment. Study one also reported on whether the regions suggested by the statistical review to inform treatment selection would be useful when applied to a prior MDD treatment study. Findings suggested functioning of the identified brain regions can help inform treatment selection, but method differences among studies included in the review hinder application of resulting regions. In an assessment of the course of MDD, the second study documented depression symptoms and quality of life across 9-14 years after treatment and found at least minimal depression symptoms as well as impairments in quality life commonly continued after treatment. In light of persistent symptoms and impairment, the third study aimed to identify neural features of MDD that did not respond to treatment, as well as neural features that were responsive to treatment. The third study found that therapy directly affects cognitive control processes, but may not affect brain regions associated more with emotion-driven processes. Clinical recommendations pertain to treating depression symptoms that continue after treatment toward asymptomatic recovery. Future research directions pertain to neuroscience informed treatment selection, current therapy and medication practices, and the larger picture of persistent depression symptoms broadly.

Depression is common in haemodialysis (HD) patients and is often unrecognised and undertreated, though associated with excess morbidity and mortality. Diagnosis is challenging due to symptom overlap with kidney failure, with fatigue being the most common overlapping symptom. Research on the effectiveness of antidepressant medication in this setting is sparse. A recent systematic review advocated well-designed Randomised Controlled Trials (RCTs) in this setting. The studies reported in this thesis had a number of aims. The main aim was to undertake a multicentre feasibility randomised, double blind, placebo-controlled trial of sertraline in patients on HD with Major Depressive Disorder (MDD). To identify suitable patients for this, a screening phase was required, which also allowed determination of the prevalence of depression in this setting and of the relative effectiveness of screening tools Patient Health Questionnaire-2 (PHQ-2), Patient Health Questionnaire-9 (PHQ-9), and Beck Depression Inventory-II (BDI-II). It also allowed examination of the relationships of fatigue in this setting (assessed mainly by the Multidimensional Fatigue Inventory (MFI), including those with a diagnosis, and management of depression. The finding, during screening, that a large proportion of the HD cohort was already on antidepressant treatment, presented the opportunity to study 'real-life' practice patterns in the management of antidepressant treatment in this setting. Recruitment into the RCT was difficult. 1,355 patients in five HD centres were considered for screening, but 243 of these were excluded, mainly because of their inability to read and understand English. Of the remaining 1,110 patients, 709 consented to screening. 231 of these screened positive for high depression symptoms but 130 were not considered for the trial phase, mainly because of concurrent treatment for depression (68 patients), and other contraindicated conditions and medication. In addition, 38 patients declined to take part in the psychiatric interview necessary for diagnosis of MDD. Of the 63 who underwent the diagnostic interview, 37 (58.7%) were diagnosed with MDD and 30 consented to enter the RCT and were randomised into sertraline or placebo groups. This was half of the anticipated recruitment into the RCT. Twenty-one patients (70%) completed the six-month study, eight of 15 in the sertraline group and 13 of 15 in the placebo group (p < 0.05). Drop out was mainly due to adverse or serious adverse events. Depression scores (BDI-II and Montgomery-Åsberg Depression Rating Scale (MADRS)) improved significantly in both the sertraline and placebo groups over six months but there were no significant differences between the treatment groups. There was a slight suggestion of more rapid improvement over the first two months on sertraline, but this was not significant. Fatigue scores were high in all sub-domains - with only a weak relationship with age and comorbidity. Mental fatigue was the strongest independent predictor of high depressive symptoms (BDI-II ≥16, PHQ-9 ≥8), while physical fatigue had the strongest relationship with dialysis recovery time, and survival. Distinguishing between these components of fatigue may have a role in refining the diagnosis and management of MDD. Forty-one of the 76 patients on antidepressant medication at screening were followed up for a mean of 14±5 months. Ten different antidepressant agents were being taken - the most common being Citalopram (39%). Most had been prescribed by GPs. Two-thirds of patients either deteriorated or failed to improve in terms of BDI-II scores during follow-up, many of whom had had no adjustment of medication during this time. Diagnostic evaluation at follow-up showed 37% to be suffering from current or recurrent major depressive episodes (MDE), 48% to have evidence of past MDE, and 15% to have no evidence of ever having been depressed. These empirical studies confirm that depression is very common in HD patients. Its diagnosis is complicated due to symptom overlap with the uraemic syndrome. Fatigue seems to be a key area of overlap with symptoms of depression with a complex relationship. There was no obvious benefit from antidepressants in this feasibility RCT and there was a high drop-out rate due to adverse events, particularly in the sertraline group. These findings raise concerns about the benefits and risks of antidepressants in patients on HD. Current practice patterns may be subjecting patients to substantial risk for little or no benefit. Identifying whether antidepressant medication is effective in this context is a major clinical need, hence the requirement for a definitive study. There is no doubt that to undertake a definitive study would pose considerable recruitment challenges. The findings presented here emphasise the importance of finding ways to overcome these challenges that might include efforts to incorporate patients already taking antidepressants.