by Mark Frye, M.D., Psychiatry and Psychology, Mayo Clinic
Racing thoughts can mean different things to different people. For some people, these are repetitive thoughts that just will not be purged from the mind, no matter how hard a person tries. To others, racing thoughts may be those that constantly and quickly bombard them, making concentration or focus difficult. To get to the root of what's causing your racing thoughts, and to determine the best treatment, the first step is to make sure your health care provider understands exactly what you're experiencing.
Disjointed, constantly changing thoughts with no unifying theme (for example, "I need to do this project and finish it, then work on this one, and then I have to go shopping, and I need to call my great aunt who lives in London") can be a sign of the manic phase of bipolar disorder. Manic thoughts may cascade rapidly through your mind, inhibiting your ability to perform daily activities or routines. In people who have bipolar disorder, racing thoughts often are accompanied by other symptoms, such as extreme optimism, inflated self-esteem, poor judgment, rapid speech, irritability, and inability to concentrate.
In addition to their speed or frequency, the content of these thoughts can be clues to the underlying cause. Thoughts that have a negative theme or pattern (for example, "I'm a bad person" or "I've done terrible things") could suggest depression, as could unrelenting thoughts of guilt or sadness. Sometimes these negative thought patterns in depression are not so much racing (i.e. going fast) as they are ruminative or unrelenting.
For some, racing thoughts are actually one thought or idea that is repeated constantly and quickly in their mind and just won't stop. That's considered an obsessional thought and may point to an anxiety disorder, such as obsessive-compulsive disorder (OCD). People with OCD have unreasonable and uncomfortable thoughts and fears (obsessions) that lead to repetitive behaviors (compulsions). Typically these obsessions focus on symmetry, orderliness and/or cleanliness and have associated checking behavior or very regimented hygiene practices.
In summary, racing thoughts can be a symptom of bipolar disorder, depression, OCD, or a variety of other mood and anxiety disorders. Treatment is available for each of these conditions. You may want to seek care from a mental health specialist to talk through your symptoms to determine the cause. From there, you and your provider can work on finding appropriate treatment options.