Peter Drummond

Diet, sleep, and exercise are lifestyle factors important for the prevention and treatment of psychiatric disorders, including major depressive disorder, anxiety disorders, bipolar disorder, and schizophrenia. These lifestyle factors can contribute to dysregulation in important physiological mechanisms associated with psychiatric disorders and influence neuroprogression. We review research highlighting the important role of these lifestyle factors for different psychiatric conditions, and examine the potential mechanisms behind their therapeutic effects, with a particular emphasis on how they may each influence neuroprogression.

Laser Doppler flowmetry has been employed for many years to assess cutaneous microvascular function in health and disease. It is often used in conjunction with transdermal iontophoresis or microdialysis of acetylcholine, as this provides information about the integrity both of the microvascular endothelium and the cutaneous sensory nerve supply. Unfortunately, widespread application of these techniques has been impeded by methodological difficulties – particularly concerning errors introduced by nonspecific responses to iontophoresis and the relatively poor reproducibility of spot measures of blood flow, and a lack of standardisation both in the form of drug delivery and the expression of blood flow data. Nevertheless, transdermal iontophoresis of acetylcholine appears to be useful for detecting the extent of microvascular disturbances in patients with cardiovascular disease, and for identifying deficits in small fiber function in patients with peripheral neuropathy. As this technique is safe and non-invasive, it holds great promise as tool for assessing microvascular and neural responses that reflect important elements of cardio- and neurovascular health.

Blushing refers to reddening of the face in emotionally charged situations, typically in association with feelings of embarrassment, guilt or shame. The reddening is due to an accumulation of red blood cells in the superficial venous plexus in the facial skin. This appears to involve an active dilatation of the arterial supply because vascular pulsations increase markedly during blushing (Figure 2.1). In addition, as facial veins are supplied with β-adrenoceptors (Mellander et al., Reference Mellander, Andersson, Afzelius and Hellstrand1982), a β-adrenergic mechanism that contributes to the dilatation of veins may increase their capacity to hold blood...

Although sensory and autonomic nerve fibres generally do not interact directly, both may exert influences on blood flow during inflammation. For example, the sympathetic neurotransmitter noradrenaline/norepinephrine evokes axon reflexes, a response that involves release of vasoactive neuropeptides from the peripheral terminals of primary nociceptive afferent fibres. As well as boosting inflammation, this mechanism could play a role in normal renal function and heat dispersal from the skin. In certain disease states, aberrant communication between sensory and autonomic nerves might not only aggravate symptoms but also contribute to clinical deterioration by altering local circulatory dynamics. For example, in certain forms of neuropathic pain, an aberrant expression of α1-adrenoceptors on primary nociceptive afferents may provide a framework for cross-talk between sensory and autonomic nerve fibres. In addition to evoking pain and other unpleasant symptoms, this cross-talk could aggravate inflammation and disrupt nutritive perfusion of affected tissues. Finally, in disorders such as cluster headache, intense bursts of trigeminal nociceptive activity may trigger trigeminal-parasympathetic vasodilator reflexes which, in turn, provoke secondary vascular disturbances that amplify pain. A clearer understanding of sensory-autonomic interactions both in health and disease may provide a basis for new treatment approaches for conditions that respond poorly to conventional treatments.

Migraine is complex—attacks are often heralded by premonitory and prodromal disturbances and may be associated with heightened sensitivity to light, noise, and smells; with allodynia and hyperalgesia that spread from the head and neck to other parts of the body; and with dizziness, vertigo, and gastrointestinal complaints. Many of these symptoms persist subclinically between episodes of headache and may increase susceptibility to recurrent attacks and to comorbid conditions such as motion sickness. Elucidating this complexity is a challenging task. This chapter reviews neural mechanisms that might underlie some of the major symptoms of migraine—premonitory and prodromal changes, headache, sensory hypersensitivity, gastrointestinal disturbances, and vestibular instability. It then discusses how these symptoms might interact during attacks of migraine.

Rosacea is a chronic and progressive disorder characterized by extremely sensitive skin, burning and stinging sensations, and persistent flushing of the cheeks, nose, chin or forehead accompanied by acne-like facial papules or pustules (Elewski et al., 2010; Wilkin, 1994). Primary diagnostic features include one or more of the following signs: frequent transient flushing; persistent redness; papules and pustules; and prominent facial capillaries. Secondary features may include: burning or stinging sensations; elevated red plaques; rough and scaly ‘dry’ skin; facial swelling; ocular discomfort; lid inflammation and red eyes; and skin thickening (Wilkin et al., 2002). A standard classification system for rosacea, developed by the National Rosacea Society Expert Committee on the Classification and Staging of Rosacea, lists four subtypes: erythematotelangiectatic rosacea, characterized by persistent flushing, central facial redness and small blood vessels near the surface of the skin; papulopustular rosacea, characterized by persistent facial redness and red bumps (papules), some filled with pus (pustules); phymatous rosacea, associated with thickened skin, particularly around the nose (rhinophyma); and ocular rosacea, where the main features are red, dry irritated eyes and eyelids (Wilkin et al., 2002). Patients may have more than one subtype, or may progress from one subtype to another. As flushing often aggravates other symptoms of rosacea, many people with rosacea avoid vasodilator agents such as alcohol and foods high in histamine or nitrate content or that are highly spiced. They also avoid soaps, lotions and creams that irritate the skin or that dilate blood vessels directly, exercise, exposure to environmental stimuli that increase skin blood flow (e.g., extremes of heat or cold, strong winds and sunlight), and psychological factors that may aggravate symptoms (e.g., stress, anxiety and emotions such as anger and embarrassment) (Culp & Scheinfield, 2009; Scharschmidt et al., 2011). They may also avoid interacting with other people due to concerns about their appearance. Not surprisingly, then, the symptoms of rosacea can impact severely on self-esteem and quality of life.