By Pat Anson, PNN Editor

Does waking up with pain everyday put you in a bad mood? Do you lose your temper easily or worry a lot?

It could be a sign that chronic pain has created a chemical imbalance in your brain that makes it harder for you to keep negative emotions in check, according to a new study by Australian researchers.

“Chronic pain is more than an awful sensation,” says senior author Sylvia Gustin, PhD, a neuroscientist and associate professor at the University of Sydney’s School of Psychology. “It can affect our feelings, beliefs and the way we are. 

“We have discovered, for the first time, that ongoing pain is associated with a decrease in GABA, an inhibitive neurotransmitter in the medial prefrontal cortex. In other words, there's an actual pathological change going on.”

Gustin and her colleagues at Neuroscience Research Australia (NeuRA) used advanced neurological imaging to scan the brains of 48 people. Half of them lived with a chronic pain condition, while the other half had no history of chronic pain and served as a control group.

Their findings, recently published in the European Journal of Pain, showed that participants with chronic pain had significantly lower levels of GABA than the control group – a pattern that was consistent regardless of the type of chronic pain. 

Neurotransmitters help communicate and balance messages between cells in the brain and central nervous system. While some amplify signals (excitatory neurotransmitters), others weaken them (inhibitive neurotransmitters). GABA, or γ-aminobutyric acid, is one of the latter. It acts in the brain as emotional regulator that helps dial down our emotions.

“A decrease in GABA means that the brain cells can no longer communicate to each other properly,” Gustin explained in a news release. “When there’s a decrease in this neurotransmitter, our actions, emotions and thoughts get amplified.”

While the link between chronic pain and decreased levels of GABA has previously been found in animals, this is the first time it’s been demonstrated in humans. Gustin hopes the findings will encourage people with chronic pain who may be experiencing mental health issues. 

“It's important to remember it’s not you – there’s actually something physically happening to your brain,” she says. “We don't know why it happens yet, but we are working on finding solutions on how to change it.”

GABA is not the only neurotransmitter that’s impacted by chronic pain. In a previous study, Gustin and her research team found that levels of glutamate, the main excitatory neurotransmitter, are also lower than average in people with chronic pain. Low glutamate levels are linked to increased feelings of fear, worry and negative thinking.

“Together, our studies show there's really a disruption in how the brain cells are talking to each other,” says Gustin. “As a result of this disruption, a person’s ability to feel positive emotions, such as happiness, motivation and confidence may be taken away – and they can’t easily be restored.” 

Medication can help relieve chronic pain, but there are currently no drugs that directly target GABA and glutamate levels in the brain. Gustin and her team are developing an online emotional recovery program as a non-pharmaceutical option for treating neurotransmitter disruption. 

“The online therapy program teaches people skills to help self-regulate their negative emotions,” says Gustin. “The brain can't dampen down these feelings on its own, but it is plastic – and we can learn to change it.”