ORCID Profile
0000-0002-1026-2798
Current Organisation
Northumbria University
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Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2014
Publisher: Wiley
Date: 28-07-2014
DOI: 10.1002/HUP.2417
Publisher: MDPI AG
Date: 11-11-2013
DOI: 10.3390/NU5114429
Publisher: Elsevier BV
Date: 06-2009
DOI: 10.1016/J.PHYSBEH.2009.02.028
Abstract: The notion that chewing gum may relieve stress was investigated in a controlled setting. A multi-tasking framework which reliably evokes stress and also includes performance measures was used to induce acute stress in the laboratory. Using a randomised crossover design forty participants (mean age 21.98 years) performed on the multi-tasking framework at two intensities (on separate days) both while chewing and not chewing. Order of workload intensity and chewing conditions were counterbalanced. Before and after undergoing the platform participants completed the state portion of the State-Trait Anxiety Inventory, Bond-Lader visual analogue mood scales, a single Stress Visual Analogue Scale and provided saliva s les for cortisol measurement. Baseline measures showed that both levels of the multi-tasking framework were effective in significantly reducing self-rated alertness, calmness and contentment while increasing self-rated stress and state anxiety. Cortisol levels fell during both levels of the stressor during the morning, reflecting the predominance of a.m. diurnal changes, but this effect was reversed in the afternoon which may reflect a measurable stress response. Pre-post stressor changes (Delta) for each measure at baseline were subtracted from Delta scores under chewing and no chewing conditions. During both levels of stress the chewing gum condition was associated with significantly better alertness and reduced state anxiety, stress and salivary cortisol. Overall performance on the framework was also significantly better in the chewing condition. The mechanisms underlying these effects are unknown but may involve improved cerebral blood flow and/or effects secondary to performance improvement during gum chewing.
Publisher: Wiley
Date: 03-2012
DOI: 10.1002/HUP.1261
Abstract: Cannabis and 3,4-methylenedioxymeth hetamine (MDMA) use is associated with psychobiological and neurocognitive deficits. Assessments of the latter typically include tests of memory and everyday cognitive functioning. However, to date, little attention has been paid to effects of drug use on psychological stress reactivity. We report three studies examining the effects of recreational use of cannabis and MDMA on mood and psychological responses to multitasking using a cognitively demanding laboratory stressor that provides an analogue for everyday situations involving responses to multiple stimuli. The effects of the multitasking framework on mood and perceived workload were assessed in cannabis (N=25), younger (N=18) and older (N=20) MDMA users and compared with non-target drug controls. Compared with respective control groups, cannabis users became less alert and content, and both MDMA groups became less calm following acute stress. Unexpectedly, the stressor increased ratings of calm in cannabis users. Users also scored higher than their controls with respect to ratings of resources needed to complete the multitasking framework. These findings show, for the first time, that recreational use of cannabis and MDMA, beyond the period of intoxication, can negatively influence psychological responses to a multitasking stressor, and this may have implications for real-life situations which place high demands on cognitive resources.
Publisher: MDPI AG
Date: 17-04-2020
DOI: 10.3390/JCM9041154
Abstract: The aim of this study was to examine the effects of hangover on mood, multitasking ability, and psychological stress reactivity to cognitive demand. Using a crossover design and semi-naturalistic methodology, 25 participants attended the laboratory in the morning following a night of (i) alcohol abstinence and (ii) alcohol self-administration during a typical night out (with order counterbalanced across participants). They completed a four-module multitasking framework (MTF, a widely used laboratory stressor) and a battery of questionnaires assessing mood, hangover symptom severity, and previous night’s sleep. The effects of the MTF on mood and perceived workload were also assessed. Participants in the hangover condition reported significantly lower alertness and contentment coupled with a higher mental fatigue and anxiety. Multitasking ability was also significantly impaired in the hangover condition. Completion of the cognitive stressor increased reported levels of mental demand, effort, and frustration, and decreased perceived level of performance. MTF completion did not differentially affect mood. Lastly, participants rated their sleep as significantly worse during the night prior to the hangover compared with the control condition. These findings confirm the negative cognitive and mood effects of hangover on mood. They also demonstrate that hangover is associated with greater perceived effort during task performance.
Publisher: Elsevier BV
Date: 10-2013
DOI: 10.1016/J.APPET.2013.05.016
Abstract: Previous research has suggested that multivitamin (MV) supplementation may be associated with beneficial effects for mood and general well-being, although treatment durations have typically been less than 90 days, s les have often been restricted to males only and acute effects have not been adequately differentiated from chronic effects. In the current study a MV supplement containing high levels of B-vitamins was administered daily to 138 healthy young adult participants between the ages of 20 and 50 years over a 16-week period. Chronic mood measures (GHQ-28, POMS, Chalder fatigue, PILL, Bond-Lader and custom visual analogue scales) were administered pre-dose at baseline, 8- and 16-weeks. Changes in Bond-Lader and VAS in response to a multi-tasking framework (MTF) were also assessed at 8- and 16-weeks. For a subset of participants, at-home mobile-phone assessments of mood were assessed on a weekly basis using Bond-Lader and VAS. No significant treatment effects were found for any chronic laboratory mood measures. In response to the MTF, a significant treatment x time interaction was found for STAI-S, with a trend towards a greater increase in stress ratings for male participants in the MV group at 16 weeks. However, this finding may have been attributable to a larger proportion of students in the male MV group. In contrast, at-home mobile-phone assessments, where assessments were conducted post-dose, revealed significantly reduced stress, physical fatigue and anxiety in the MV group in comparison to placebo across a number of time points. Further research using both acute and chronic dosing regimens are required in order to properly differentiate these effects.
Publisher: Informa UK Limited
Date: 2009
DOI: 10.1080/10253890801976926
Abstract: The responses to inhalation of 35% carbon dioxide (CO(2)) as a stressor were compared in female irritable bowel syndrome (IBS) patients and healthy controls to assess potential differences in cardiovascular, neuroendocrine and behavioural responses to stress. A total of 22 women (12 patients with ROME II defined diarrhoea-predominant IBS and 10 aged-matched controls) were challenged with a single vital capacity breath of 35% CO(2) (with 65% oxygen). Beat-to-beat blood pressure and heart rate were recorded prior to, during and after the inhalation. Serum cortisol concentration and behavioural ratings were measured pre- and post-inhalation. A typical pattern of responses to CO(2) was observed, characterised by a reduction in heart rate and increases in serum cortisol and anxiogenic symptoms however, these responses did not differ between groups. Both groups also demonstrated an increase in systolic blood pressure however, this response was significantly enhanced in IBS patients compared to healthy controls (P < 0.05). These findings demonstrate that females with diarrhoea-predominant IBS have an exaggerated pressor response to 35% CO(2) stress challenge, suggesting a more stress-responsive sympathetic nervous system.
Publisher: Wiley
Date: 21-06-2013
DOI: 10.1002/PTR.5029
Abstract: Little research exists in humans concerning the anxiolytic, antidepressant, sedative, and adaptogenic actions the traditional Ayurvedic medicine Bacopa monnieri (BM) possesses in addition to its documented cognitive-enhancing effects. Preclinical work has identified a number of acute anxiolytic, nootropic, and adaptogenic effects of BM that may also co-occur in humans. The current double-blind, placebo-controlled cross-over study assessed the acute effects of a specific extract of BM (KeenMind® - CDRI 08) in normal healthy participants during completion of a multitasking framework (MTF). Seventeen healthy volunteers completed the MTF, at baseline, then 1 h and 2 h after consuming a placebo, 320 mg BM and 640 mg of BM. Treatments were separated by a 7-day washout with order determined by Latin Square. Outcome measures included cognitive outcomes from the MTF, with mood and salivary cortisol measured before and after each completion of the MTF. Change from baseline scores indicated positive cognitive effects, notably at both 1 h post and 2 h post BM consumption on the Letter Search and Stroop tasks, suggesting an earlier nootropic effect of BM than previously investigated. There were also some positive mood effects and reduction in cortisol levels, pointing to a physiological mechanism for stress reduction associated with BM consumption. It was concluded that acute BM supplementation produced some adaptogenic and nootropic effects that need to be replicated in a larger s le and in isolation from stressful cognitive tests in order to quantify the magnitude of these effects. The study was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12612000834853).
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Mark Wetherell.