Having a bad attitude can do more than just make you an unpleasant person to be around; it can mess with your brain chemistry too.

“When we think in negative ways, we are often consciously or unconsciously frightened or worried about an issue or an outcome,” says clinical psychologist Dr. Carla Manly. “Such negative, fear-based thoughts keep the brain in a fearful state.”

But that’s not all – turns out, negativity can increase your risk of stroke, decrease your cognitive functioning, and more. Don’ believe us? Here’s why you might reconsider viewing the cup as half empty.

It encourages more negative thoughts in the future
Neuron connections form and become more pronounced with the repetition of certain thoughts or the reimagining of experiences. “If the persistently-visited thoughts are negative, that forms a quick and easy, embedded path to revisit and reinforce negative thoughts,” says licensed psychologist Dorian Crawford. “Increased negativity reinforces negativity and makes it more efficient to access as the dominant thought pattern.”

It raises cortisol levels
Cortisol, also known as the stress hormone, directly affects the brain. “Negative processing is often associated with stress, and stress often results in an increased release of cortisol,” says Crawford. “This increases white matter in the brain. Neuron activity is less efficient in white (versus grey) matter, making your brain susceptible to responding less effectively to stress or difficulties.”

It triggers a fight or flight response
Negative thoughts can also involve the thalamus, which helps our bodies prepare for a fight or flight option in response to danger. “If your brain repeatedly perceives stress and negative events as dangerous, the thalamus will trigger the fight or flight response, flooding the body with adrenaline and possibly triggering a panic attack,” says Crawford. “At the very least, anxiety is heightened, which reduces the brain’s ability to manage complex processing.”

It increases your risk of stroke
According to research, anger and hostility can lead to a greater risk of stroke. “The way in which this happens is that negative emotions activate the hypothalamic pituitary adrenal (HPA) axis, your body’s built-in stress response system,” says licensed psychologist Nicole Issa. “The changes in neurological and endocrine systems lead to risk factors of stroke.”

It can decrease your cognitive functioning
When you have emotionally-charged thoughts, most often negative ones, your limbic system takes over. “Your prefrontal cortex, which is used for cognitive functioning and organization, has energy diverted away from it,” says Issa. “As a result, you can’t think as clearly.”

How do you boost your mood when you’re feeling down? Leave your best tips in the comments below!

xx, The FabFitFun Team