Intrusive Thoughts: Normal or Not?

Have you ever envisioned a stranger falling off a subway platform and onto the tracks below just as the next train is about to arrive? Have you ever had a fleeting thought about driving your car over the side of a suspension bridge or into oncoming traffic? Or maybe you've pictured yourself accidentally dropping a baby you're holding or kissing a handsome colleague at the office.

These may sound like the musings of an unstable mind, but they're actually quite normal. They're called intrusive thoughts, which means they're ideas, images, doubts or impulses that the person doesn't call up voluntarily, explains Jonathan Abramowitz, professor and associate chair of psychology at the University of North Carolina--Chapel Hill. And they happen to everyone now and then.

"They're often unpleasant or disturbing but they don't have to be," Abramowitz says. "They tend to reflect things that are important to us. It's probably a survival mechanism: To think about bad things helps us be more on alert in case it happens."

Unwanted, intrusive thoughts tend to involve subjects related to cleanliness or contamination, aggression or harm, religion or blasphemy, or sexually repugnant themes, notes Adam Radomsky, a professor of psychology in the Centre for Clinical Research in Health at Concordia University in Montreal. In other instances, intrusive thoughts may relate to new responsibilities you've adopted in your life -- frightening thoughts about harm coming to your baby if you're a new parent, for example, or something bad happening to an elderly family member whose care you've recently been entrusted with.

"Often, stressful situations can trigger intrusive thoughts, and sometimes the trigger can be obvious -- walking past a fire extinguisher and having the sudden image that your house is on fire," Radomsky adds.

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While vacationing in the Mediterranean this spring, Erica McCurdy walked up to the mouth of a volcano. As she peered into it, she saw steam rising and wondered about the magnitude of the last eruption. Suddenly, she was struck by the thought, "What would happen if I just jumped in?" She immediately laughed to herself and dismissed the notion, saying to herself, "Wow -- that would be a bad idea!" "We all have these crazy, fleeting thoughts, and they only become a problem when we feel motivated to act on them," says McCurdy, 47, an Atlanta-based divorce and business coach.

"If an unpleasant thought pops into your head and you basically ignore it, then it doesn't tend to be a problem," says Norman B. Schmidt, research professor of psychology at Florida State University in Tallahassee. "For some people, however, they feel that they need to manage them or do something about them. Unfortunately, this often gets them caught up into a vicious cycle where the 'management' of the thoughts leads to more [unwanted] thoughts." (In fact, research suggests that trying to suppress intrusive thoughts tends to backfire, making them return with greater frequency and intensity.)

Intrusive thoughts can "escalate into clinical problems when the person responds to them in maladaptive ways," Abramowitz says. In other words, intrusive thoughts can become problematic when the person puts too much stock in them and feels that he or she needs to fight against the thought or change his or her behavior to prevent the thought from turning into reality. Or, some people may begin to believe that the intrusive thoughts say something meaningful or bad about them, which also leads to distress.

This can happen if, say, a father feels he needs to say 20 prayers while bathing his child because he has experienced scary images of his baby's head going underwater in the bath. Similarly, "if an intrusive thought of driving off a bridge means you no longer drive to visit your mother because it would mean crossing a bridge, then the thoughts are becoming a problem," says researcher Jessica Beadel, a doctoral candidate in clinical psychology at the University of Virginia. "Or if an intrusive image of a plane crash means you call your spouse who travels for work 12 times a day to check that he or she is OK, then the thoughts are leading to behaviors that impair quality of life."

[See: 11 Simple, Proven Ways to Optimize Your Mental Health.]

In such instances, intrusive thoughts may be a symptom of obsessive-compulsive disorder, or OCD, Abramowitz says. "With OCD, [intrusive thoughts] lead to rituals to avoid acting on the thoughts or efforts to get rid of the disturbing thoughts or to neutralize them." Avoidance and excessive checking behaviors also tend to worsen intrusive thinking.

Meanwhile, persistent, trauma-related intrusive thoughts are common among those suffering from post-traumatic stress disorder, or PTSD. A 2016 study from the University of California--San Diego found that when people with PTSD and low executive functioning tried to suppress their intrusive thoughts, these unwanted thoughts became more frequent and tenacious. By contrast, people struggling with addictions may have intrusive thoughts about using the substances they're hooked on, whereas those who have body dysmorphic disorder or eating disorders may experience intrusive thoughts about their bodies, Abramowitz notes.

To determine whether your intrusive thoughts have ventured beyond the realm of "normal," it helps to consider whether the images or ideas are emotionally distressing or whether they are impairing or interfering with your ability to function or do things you normally do, such as sleeping, socializing, working or going to school. If they are, your best bet is to seek out a cognitive-behavioral therapist, Radomsky says. "This person, usually a psychologist, can help you reevaluate how you're reacting to these thoughts and find ways to treat them like they are less important."

[See: 9 Things That Are Surprisingly Good for Your Health.]

On the other hand, if these fleeting, bizarre thoughts aren't having an adverse effect on you, there's nothing to be concerned about. Simply continue shrugging them off and moving on to new thoughts as they occur. Indeed, many people treat intrusive thoughts as if they were "clouds passing in the sky," Abramowitz says, which is as it should be. "What sense does it make to judge clouds as good or bad?"

"The best strategy is to learn how to accept intrusive thoughts for what they are -- mental noise -- without judging them based on their content," Abramowitz adds. "As soon as you start analyzing them, you throw wind into their sails and puff them up" -- something they don't deserve.

Besides, as McCurdy, the divorce coach who stepped back from the brink of a volcano, says, "It's a mistake to let intrusive thoughts take time away from all the other wonderful thoughts you have in a day."

Stacey Colino is a freelance Health + Wellness reporter at U.S. News. You can connect with her on LinkedIn or email her at staceycolino@gmail.com.