Those "think positively" people - Little problems that lead to explosive reactions - What is a toxic person?

Positive thinking leads to denial which creates negative emotions in your body eventually leading to depression. What?? Sounds like a great first topic. Little spats in a relationship that lead to massive blowups have an origin. The unspoken words are what cause those big explosions. It's time to connect emotionally rather than logically to diffuse the emotional bombs before they explode. What is toxic? Do we call people toxic just to avoid our own personal growth? A listener challenges me on the topic.