As a clinical psychologist, I often have clients say they are having trouble with thoughts "on a loop" in their head, which they find difficult to manage.
While rumination and overthinking are often considered the same thing, they are slightly different (though linked). Rumination is having thoughts on repeat in our minds. This can lead to overthinking — analysing those thoughts without finding solutions or solving the problem.
It’s like a vinyl record playing the same part of the song over and over. With a record, this is usually because of a scratch. Why we overthink is a little more complicated.
We’re on the lookout for threats.
Our brains are hardwired to look for threats, to make a plan to address those threats and keep us safe. Those perceived threats may be based on past experiences, or may be the "what ifs" we imagine could happen in the future.
Our "what ifs" are usually negative outcomes. These are what we call "hot thoughts" — they bring up a lot of emotion (particularly sadness, worry or anger), which means we can easily get stuck on those thoughts and keep going over them.
However, because they are about things that have either already happened or might happen in the future (but are not happening now), we cannot fix the problem, so we keep going over the same thoughts.
Who overthinks?
Most people find themselves in situations at one time or another when they overthink.
Some people are more likely to ruminate. People who have had prior challenges or experienced trauma may have come to expect threats and look for them more than people who have not had adversities.