Good or bad, happy or sad, our memories are a huge part of who we are. They can help us repeat our successes, motivate us to learn from our mistakes and provide the framework for our sense of ourselves as individuals.

But when painful or counter-productive memories echo over and over in our heads, they drain our mental energy and lessen our joy. Self-defense: Learn how toxic memories form — then develop skills to defuse their power.

ORIGINS OF MEMORIES

Much of the way we see ourselves is rooted in childhood experiences, and the memories of those early events can be intense. Not every unpleasant childhood experience becomes a toxic memory, however. In fact, similar situations can create similar memories — yet produce very different effects.

Example: Two women remember feeling humiliated in first grade for being unable to read. Whenever the first woman thinks of this, she also reminds herself of how she excelled at math. For her, this early memory is tied to feelings of success. But when the second woman recalls her six-year-old self, she views those first failures with reading as the start of every struggle she has ever faced and every challenge she has ever avoided. For her, this unhappy memory is toxic.

Not all toxic memories are rooted in childhood. They can form at any time, especially during emotional upheaval. For instance: The memory of losing her job turns toxic if a woman feels enraged whenever she thinks of it. The memory of a bitter divorce becomes toxic if a woman is too afraid ever to date again. The memory of her father’s dying is toxic if a woman sobs uncontrollably every time she pictures his face, even years after his death.

An exceptionally traumatic event, such as being a victim of a violent crime, understandably can cause extreme fear, anger and sadness. But the memory turns especially toxic if a woman blames herself — believing, for instance, “I was sexually assaulted because I danced too provocatively” — rather than rightfully blaming the assailant.

HOW MEMORIES CAN HURT

If poisonous memories repeatedly invade our thoughts, reinforcing negative feelings about ourselves or others, we may have…

  • Diminished pleasure in life, as even happy occasions are overshadowed by images from the past. Example: At her daughter’s wedding, a woman obsesses about how aloof her own mother was. Such thoughts increase a person’s risk for depression and/or anxiety disorders.
  • Low self-esteem and missed opportunities for growth. Example: Having always been picked last for teams in gym class, a woman habitually labels herself as clumsy — and refuses to exercise or to socialize with friends on the golf course.
  • Inability to respond appropriately to new situations. Example: Continued resentment over having been laid off may negatively affect a woman’s manner and the impression she makes on job interviews.
  • Chronically elevated levels of stress hormones. These have damaging effects on blood pressure, blood sugar, digestion and immunity, increasing risk for heart disease, diabetes and gastric disorders.

BREAKING THE HABIT

A toxic memory turned constant companion is as much a bad habit as a bad memory — and like any bad habit, it can be broken. Steps…

1. Select a favorite positive memory. You can choose an event that specifically contradicts your toxic memory (for instance, the day you learned to ski despite being a “hopeless klutz”)… or choose a completely unrelated experience, such as your first date with your husband.

2. Write down as many details as you can recall. Where did you go? What did you wear? Did you dance to a certain song or see a stunning sunset? How did that first kiss feel? Tap into all your senses.

3. Practice conjuring up this happy memory. Let this personal “movie” play inside your head during relaxed moments. Soon you’ll be able to recall it vividly at will, even when stressed or depressed.

4. Mentally hit an “eject” button whenever a toxic memory pops into your head, replacing it with thoughts of the happy memory.

FULFILLING EMOTIONAL NEEDS

If the technique above isn’t working, your toxic memory may be more than a bad habit — it may be fulfilling some unmet need. Ask yourself, “How am I benefiting by holding onto this painful memory?” This insight will help you explore more productive ways to meet that need, thus diminishing the power of the toxic memory. Consider…

Does thinking of yourself as unlucky let you avoid taking responsibility for your life? On a sheet of paper, make two columns, labeled “good luck” and “bad luck,” then list examples from your own life of each type of experience. You will see that your whole life hasn’t been a series of misfortunes. Next, identify the role played by your own efforts — rather than good luck — in creating each positive experience… and give yourself due credit.

Is there a certain pleasure for you in resenting other people for past unpleasantness? (Be honest with yourself!) Develop a habit of doing small favors that make people respond to you in a positive way. Smile at everyone you pass on the sidewalk, yield to other drivers trying to enter your lane, say a sincere “thank you” to a surly cashier. A conscious and voluntary decision to be of service to others can help you overcome old resentments, relegate toxic memories to the past and find pleasure in the here and now.

If you feel traumatized: After an extremely traumatic experience, it is normal to fixate on the event for a time. However, if you are seriously disturbed by recurrent memories of the trauma months or even years later, you may have post-traumatic stress disorder (PTSD). Symptoms include nightmares or obsessive mental reenactments of the event… frequent fear or anger… trouble concentrating… feelings of guilt, hopelessness or emotional numbness.

Defusing traumatic memories may require the help of a mental-health professional. Recommended: Cognitive-behavioral therapy (CBT), which focuses on changing harmful thought patterns rather than on lengthy exploration of past experiences. Referrals: National Association of Cognitive-Behavioral Therapists, 800-253-0167, NACBT.org. With CBT, even seriously toxic memories can become more manageable — and you can move on with your life.