If you start to scent unusual smells, you might be in the state of anxiety, scientists suggest. This happens because under stress the circuit connections in the brain are changed, according to The Daily Mail. Thus, previously neutral scents become unpleasant and the greater the stress, the larger is the change in smell.

Wen Li, a professor of psychology at the University of Wisconsin-Madison, conducted an experiment with 12 volunteers, inducing anxiety in them and scanning their brains. Stress made the neutral smells unpleasant in people's minds. And this even more intensified the stress, which in theory can provoke anxiety disorders and depression.

In the course of the experiment, the scientists observed that two distinct and typically independent circuits of the brain - one dedicated to olfactory processing, the other to emotion - become intimately intertwined under conditions of anxiety.