Thoughts that invade your mind are intrusive. Intrusive, because not only are they unhelpful, they also arrive uninvited and can drag you down the depression and anxiety rabbit hole. A good strategy is to disrupt the thoughts with a mantra of your choosing. A mantra is a word or sound repeated either silently or aloud. I like one or two syllable words or phrases. Examples include om, sunshine, brown cow, blue moon, and purple. Be sure that the word is fairly neutral in emotional meaning for you. Using the name of a beloved pet that has passed away would not be recommended as it may lead to sad thoughts. When you first become aware of unhelpful thoughts, repeat your mantra until the thoughts are dissolved - like sugar in water. Dissolution should only take a few seconds. Repeat as needed.