Pimples. Limp hair. Bloating. Not looking your best can definitely put a damper on your mood. But, there’s a twist. Science indicates our attitudes could be the cause of these annoying flaws in the first place.“Stress causes inflammation, which can both break down collagen to cause wrinkles or inflame acne,” says Amy Wechsler, M.D., a New York City dermatologist and YouBeauty Skin Advisor. On the flipside, “happiness helps skin to heal and glow.”QUIZ: Get in the Mood for BeautyIn a funk? Pleased as punch? Science explains how your feelings might be written all over your face. And body. And hair.The Blues: Proven Beauty BummerNo matter the situation it arises from—something serious like unemployment or something mild like a busy day at work—stress and depression can have major impacts on your beauty.One of the biggest drivers in the bad mood-beauty connection are feelings of anxiety and depression triggering the release of cortisol, a hormone produced in the adrenal gland atop the kidneys. Cortisol has many functions in the body and unfortunately, almost all of them are bad. For example, cortisol is known to cause the hormone changes that result in temporary hair loss, which can cause your hair to appear thinner and flatter. Having high levels of the hormone in your body has also been shown to increase appetite, boost cravings for sugar and cause fat to accumulate, especially around your midsection.MORE: The Effects of Stress on BeautyStress has a huge effect on your skin. Dermatologists at the Stanford University School of Medicine found that 22 college students’ acne became significantly more severe while studying for exams than during the rest of the semester. Some scientists believe this tension-induced acne is caused by an increase in sebum, an oily matter that is supposed to help protect skin but easily mixes with dead cells and bacteria to clog hair follicles and create pimples. The cells that make sebum are known to have receptors for stress hormones, possibly meaning they ramp up production during taxing situations. This mechanism, however, is still being debated among researchers. It is a nasty cycle: Stress brings on a pimple that won’t go away because you’re stressed—and that stresses you out.Chronic tension can also interrupt your body’s production of new collagen, a group of supportive, structural proteins located throughout your body. Without new collagen, your skin can become thinner and weaker. What’s more, being in a bad mood could cause your skin to become dehydrated. In addition to looking unsightly and feeling uncomfortable, this can affect cells’ ability to recover after injury.Feeling Good, Looking GreatMost of what scientists know about the mood-beauty connection is focused on the negative—how bad moods, stress and depression negatively affect your body. But the reverse is true, too. Less stress and depression might logically mean less acne, hair loss, skin dryness and fat accumulation. A bulk of research links good moods to behavioral decisions that translate into beauty benefits.For example, happy people have been shown to have more sex than their depressed peers. Sex causes blood vessels to widen, giving a hint of a blush or glow. It also increases blood flow throughout your body, rushing nutrients and oxygen to the skin and hair so both appear (and actually are) healthier.MORE: Doing It Does a Body GoodImproving your mood improves your eating habits. A 2007 study by Cornell marketing experts found people ate healthier—in this case choosing grapes over salty, buttered popcorn—while watching an upbeat movie (“Sweet Home Alabama”) than during a depressing one (the 1970 film “Love Story”). Healthier foods have less sugar and saturated fat, which can make you feel bloated or cause breakouts and oily skin.People in happy, energetic and relaxed moods are also more immune to the common cold than those who are angry, depressed or nervous, according to a study by scientists at Carnegie Mellon University. Escaping the all-over icky feeling that comes with being sick means you’ll continue doing activities that keep you looking your best, whether it’s going to the gym, eating right or heck, even maintaining your skin regimen.MORE: The Science of Emotional EatingAs Wechsler explains in her book, “The Mind-Beauty Connection,” scientists are just starting to dive into how emotions affect our appearance, so what we know now is just the tip of the iceberg: “We now acknowledge and have been amassing the scientific proof of the delicate yet complex intertwining of our biology and our psychology, the untold ways in which our personalities, emotions, feelings and thoughts both reflect and affect what’s going on inside our bodies.”So, for the sake of your beauty, take a deep breath, calm down and embrace a positive mindset. You have the power to feel as good as you look and look as good as you feel.