Brain imaging studies indicate that obsessive thinking is associated with a neurological dysfunction of unknown cause that forces thoughts into repetitive loops. While some people find themselves obsessing for the first time, others may have had multiple episodes, the specific content changing over time.

What is the root cause of obsessive thinking?

OCD is due to genetic and hereditary factors. Chemical, structural and functional abnormalities in the brain are the cause. Distorted beliefs reinforce and maintain symptoms associated with OCD.

Where do obsessive thoughts come from?

But many people who experience these thoughts don't have a mental health disorder, says Dr. Kerry-Ann Williams, a lecturer in psychiatry at Harvard Medical School. Intrusive thoughts are often triggered by stress or anxiety. They may also be a short-term problem brought on by biological factors, such as hormone shifts.