Peter G. Fitzgerald

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Bacterial colonisation of the intestine has a major role in the post-natal development and maturation of the immune and endocrine systems. These processes are key factors underpinning central nervous system (CNS) signalling. Regulation of the microbiome–gut–brain axis is essential for maintaining homeostasis, including that of the CNS. However, there is a(More)
OBJECTIVE Approximately 30% of patients with depression fail to respond to a selective serotonin reuptake inhibitor (SSRI). Few studies have attempted to define these patients from a biological perspective. Studies suggest that overall patients with depression show increased production of proinflammatory cytokines. We examined pro- and anti-inflammatory(More)
Dopamine (DA) holds a predominant role in the regulation of prolactin (PRL) secretion. Through a direct effect on anterior pituitary lactotrophs, DA inhibits the basally high-secretory tone of the cell. It accomplishes this by binding to D2 receptors expressed on the cell membrane of the lactotroph, activation of which results in a reduction of PRL(More)
BACKGROUND Irritable bowel syndrome (IBS) is associated with an enhanced perception to visceral stimuli and exaggerated stress response. The serotonergic neurotransmitter system has been strongly implicated as a key player in the manifestation of IBS symptomatology including visceral hypersensitivity. However the role of 5-HT(2B) receptors in visceral pain,(More)
BACKGROUND AND PURPOSE Recent studies indicate that efflux of antidepressants by the multidrug resistance transporter P-glycoprotein (P-gp) at the blood-brain barrier (BBB) may contribute to treatment-resistant depression (TRD) by limiting intracerebral antidepressant concentrations. In addition, clinical experience shows that adjunctive treatment with the(More)
BACKGROUND Although significant, the issue of health literacy (HL) among parents attending pediatric surgery outpatient clinics has received little attention. PURPOSE The objectives of this study are to determine the HL skills of parents attending the pediatric surgery outpatient clinic at McMaster Children's Hospital and to describe parent satisfaction(More)
In three separate experiments using auditory stimuli, subjects detected improbable targets in an on-going train of standard stimuli. In experiment I there were two equally improbable target stimuli, one difficult to discriminate from the standard stimuli and one easy to discriminate. Experiment II investigated the effects of discrimination difficulty using(More)
OBJECTIVES To examine the effectiveness and cost-effectiveness of short-term counselling in general practice for patients with chronic depression or combined depression and anxiety, compared with general practitioner (GP) care alone. DESIGN A randomised controlled trial and economic evaluation with an initial assessment at randomisation and follow-ups at(More)
BACKGROUND Irritable bowel syndrome (IBS) is characterized by recurrent abdominal pain and altering bowel habit with a high percentage of patients displaying comorbid anxiety. Growing clinical and preclinical evidence suggests that probiotic agents may restore the altered brain-gut communication in IBS. In this study, we evaluated the efficacy of repeated(More)