Have you noticed that when you’re having an off week, your skin seems to be misbehaving as well? You’ve had a few very stressful days, you haven’t been sleeping well, you haven’t been eating well and you haven’t had time to drink water – your skin looks dull, might be dryer or you might have some new spots. If you have a long-standing skin condition, you might be experiencing a flare too! If you struggle with any kind of skin problem, you’re probably well aware of this happening.
The brain-skin connection has been known about since ancient times but we’ve only started studying it in the last 20 or so years. Whether directly or indirectly, your mental health has an effect on your skin. Let’s discuss how this can happen:
Depression is the biggest mental health problem worldwide and a national survey found 1 in 4 people will experience a mental health problem of some kind in a year in England. Not everyone develops depression or anxiety, but everyone experiences symptoms, especially if you’re feeling stressed or down! Psychological stress is well known to exacerbate skin conditions, from acne, atopic dermatitis and eczema to psoriasis and alopecia.
There is a strong proven link between emotional stress, especially stressful life events, and acne. Studies find that an increase in stress causes an increase in the severity of acne. The way your body reacts to stress is by activating a hormone cascade called the HPA axis, where the first hormone is corticotropin releasing hormone (CRH). In recent years, we’ve found that the skin has an HPA-like axis too! CRH in the skin interacts with the sebaceous glands causing increased oil production, which promotes acne. (Jović et al. 2017; Zouboulis and Böhm 2004)
Amongst many things, your skin acts to keep good things in (water) and bad things out (pollutants, pathogens) – this is called the barrier function. It is very important for retaining water, which keeps it healthy – hydrated skin is healthy skin! Research shows that stress disturbs the barrier function by affecting the outermost layer of the skin, called the stratum corneum. Stress causes more glucocorticoids to be produced in the skin, which decreases the integrity of the stratum corneum and causes increased permeability – this means your skin cannot keep in water anymore and becomes dehydrated. (Levi et al. 2010; ‘Mechanisms by Which Psychologic Stress Alters Cutaneous Permeability Barrier Homeostasis and Stratum Corneum Integrity | Elsevier Enhanced Reader’ n.d.)
Signs of ageing include lines and wrinkles, increased pigmentation, dull skin and loss of elasticity and firmness. There are several theories on what exactly causes skin aging, but we don’t know for sure. UV radiation, reactive oxygen species, air pollution, smoking and stress are some of the known factors. Stress contributes to this process by activating certain pathways, resulting in stress-induced inflammation and damage. (Dunn and Koo 2013; ‘Brain-Skin Connection: Stress, Inflammation and Skin Aging: Ingenta Connect’ n.d.)
Your scalp is also part of your skin! Two of the main differences are that it’s a lot thicker than the skin on your body with many more blood vessels and contains more sebaceous glands, which produce oil. Although we don’t know why, many studies confirm that stressed individuals are more likely to lose hair than those that are not. (Saif et al. 2018; Schmitt et al. 2012; York et al. 1998; Malkud 2015)
Remember the stratum corneum? The scalp also has that – just as stress affects the stratum corneum in the skin on your body, it also affects the skin on your head. Stress can cause the compromise of the barrier function in your scalp, which again leads to water loss and dry skin. However, your scalp is also not capable of efficiently keeping pathogens out anymore including a fungus called Malassezia. Growth of this fungus is strongly associated with dandruff on a dry and itchy scalp. (Turner, Hoptroff, and Harding 2012)