Can't stop thinking about that time you cried in front of a girl during a Tim Burton movie on your first and only date? It might be because your brain is lacking a specific chemical, according to a study published Friday in Nature Communications. And while being unable to suppress unwanted bad thoughts can occasionally be embarrassing or unpleasant, the Miami Herald reports it can be downright disastrous for people with depression, PTSD, or schizophrenia. "Our ability to control our thoughts is fundamental to our wellbeing," Cambridge professor Michael Anderson says in a press release. Being unable to do so "causes some of the most debilitating symptoms of psychiatric diseases," he adds.
That's why it was so exciting for Anderson and his team when they discovered what they believe is the reason some people can't stop thinking about unwanted things. The BBC reports researchers studied the chemical and blood flow changes in subjects' brains as they were told to recall or not recall certain words. They concluded an "inhibitory" neurotransmitter called GABA in the hippocampus, the "memory" region of the brain, is the key, with subjects with more GABA being better at stopping unwanted thoughts. Anderson says GABA acts like "an army's foot-soldiers" against such thoughts and memories. He says the discovery could in the future lead to new ways to treat PTSD, depression, schizophrenia, and more. (A 23-year-old lost his memory. Then came the MRI.)