Sleep-wake disturbances and depression in older adults

Sleep-wake disturbances (SWD’s) are intertwined with depression in older adults, persist after remission, and predict depression severity and relapse. Little research has focused on objective measurement of sleep-wake cycles, and how they relate to depression in clinical and non-clinical samples of older adults. This thesis evaluated how depressive symptoms, psychiatric history, and a commonly used type of antidepressant relate to sleep-wake disturbances and subcortical brain volumes in older adults. Chapter 3 explored the association between antidepressant usage and SWD’s. A delay in the sleep cycle of older adults taking antidepressants was observed, as well as increased sleep-wake fragmentation. Chapter 3 provided initial evidence of quantifiable differences in the sleep-wake cycles of older adults using antidepressants. Chapter 4 examined the sleep-wake cycles of participants involved in a controlled trial of low-dose sertraline for older adults with subsyndromal depression. The sertraline condition showed a significant delay in sleep offset timing and greater activity during post-midnight hours after 3-months. Chapter 4 identified time-of-day specific activating effects with the use of sertraline in older adults. Chapter 5 examined how irregular sleep is related to active and remitted major depression. Sleep regularity was reduced in those with current major depression. Chapter 5 provides the first evidence for irregular sleep as a marker of major depression in its active phase. Chapter 6 examined caudate nucleus (CN) and nucleus accumbens (NAc) volumes using magnetic resonance imaging. Irregular sleep and a lifetime history of depression was associated with reduced volumes of the NAc, which was strongly associated with increased sleep-wake fragmentation, and low activity during the day. Chapter 6 provides the first evidence of an association between SWD’s and reduced NAc volumes in older adults with a lifetime history of depression and irregular sleep. Sleep-wake disturbances (SWD’s) are intertwined with depression in older adults, persist after remission, and predict depression severity and relapse. Little research has focused on objective measurement of sleep-wake cycles, and how they relate to depression in clinical and non-clinical samples of older adults. This thesis evaluated how depressive symptoms, psychiatric history, and a commonly used type of antidepressant relate to sleep-wake disturbances and subcortical brain volumes in older adults. Chapter 3 explored the association between antidepressant usage and SWD’s. A delay in the sleep cycle of older adults taking antidepressants was observed, as well as increased sleep-wake fragmentation. Chapter 3 provided initial evidence of quantifiable differences in the sleep-wake cycles of older adults using antidepressants. Chapter 4 examined the sleep-wake cycles of participants involved in a controlled trial of low-dose sertraline for older adults with subsyndromal depression. The sertraline condition showed a significant delay in sleep offset timing and greater activity during post-midnight hours after 3-months. Chapter 4 identified time-of-day specific activating effects with the use of sertraline in older adults. Chapter 5 examined how irregular sleep is related to active and remitted major depression. Sleep regularity was reduced in those with current major depression. Chapter 5 provides the first evidence for irregular sleep as a marker of major depression in its active phase. Chapter 6 examined caudate nucleus (CN) and nucleus accumbens (NAc) volumes using magnetic resonance imaging. Irregular sleep and a lifetime history of depression was associated with reduced volumes of the NAc, which was strongly associated with increased sleep-wake fragmentation, and low activity during the day. Chapter 6 provides the first evidence of an association between SWD’s and reduced NAc volumes in older adults with a lifetime history of depression and irregular sleep

The Effects of Precautionary Messages about Electromagnetic Fields from Mobile Phones and Base Stations Revisited: The Role of Recipient Characteristics

Precautionary messages have been shown to increase recipients\u27 threat perceptions about radio-frequency electromagnetic fields (RF-EMFs) emitted by mobile phones and mobile phone base stations. The current study explored the interplay of variables on the side of message recipients with this effect. The individual difference variables of interest were gender, trait anxiety, personal need for structure, and personal fear of invalidity. Furthermore, the study determined whether the increased threat perception is accompanied by emotional distress. A total of 298 university students answered a survey after reading either a basic text about RF-EMFs or a text including precautionary information. Linear multiple regression with interactions analyses showed that the effect of precautionary messages differed for people with different levels of trait anxiety. How trait anxiety was related to the effect of precautionary messages in turn depended on participants\u27 gender. Personal need for structure and personal fear of invalidity were mostly unrelated to the effect of precautionary messages. Regarding participants\u27 emotional distress, we found no difference in state anxiety scores between those participants who received precautionary information and those who did not. The findings show that the effects of precautionary messages on threat perception depend on individual difference variables such as recipients\u27 trait anxiety and gender. Also, the fact that precautionary communication did not result in heightened state anxiety challenges the assumption that precautionary messages induce fear or anxiety

The 2019 report of The Lancet Countdown on health and climate change: ensuring that the health of a child born today is not defined by a changing climate

The Lancet Countdown is an international, multidisciplinary collaboration, dedicated to monitoring the evolving health profile of climate change, and providing an independent assessment of the delivery of commitments made by governments worldwide under the Paris Agreement. The 2019 report presents an annual update of 41 indicators across five key domains: climate change impacts, exposures, and vulnerability; adaptation, planning, and resilience for health; mitigation actions and health co-benefits; economics and finance; and public and political engagement. The report represents the findings and consensus of 35 leading academic institutions and UN agencies from every continent. Each year, the methods and data that underpin the Lancet Countdown's indicators are further developed and improved, with updates described at each stage of this report. The collaboration draws on the world-class expertise of climate scientists; ecologists; mathematicians; engineers; energy, food, and transport experts; economists; social and political scientists; public health professionals; and doctors, to generate the quality and diversity of data required. The science of climate change describes a range of possible futures, which are largely dependent on the degree of action or inaction in the face of a warming world. The policies implemented will have far-reaching effects in determining these eventualities, with the indicators tracked here monitoring both the present-day effects of climate change, as well as the worldwide response. Understanding these decisions as a choice between one of two pathways—one that continues with the business as usual response and one that redirects to a future that remains “well below 2°C”—helps to bring the importance of recognising the effects of climate change and the necessary response to the forefront. Evidence provided by the Intergovernmental Panel on Climate Change, the International Energy Agency, and the US National Aeronautics and Space Administration clarifies the degree and magnitude of climate change experienced today and contextualises these two pathways