A potential health risk of negative ions is that proponents may overestimate their health benefits. Given the large number of ionization products and the many claims made about them, consumers can be led to believe that getting negative ions will heal anything and everything—from eliminating depression to fighting cancer. Negative ions may help people cope with seasonal depression and help the body function better, but many of these claims are unfounded and not backed by scientific evidence. For many conditions, negative-ion therapy may not hurt, but it's still imperative to talk to a doctor and explore accredited methods of treatment.
Recent research suggests that negative social exchanges may contribute to declines in cognitive functioning. Middle-aged adults who experience more frequent negative social exchanges have been found to perform worse on tests of executive function, controlling for sociodemographic characteristics, chronic health conditions, functional health limitations, health behaviors, and depression (Seeman et al., 2010; Tun et al., 2013). Frequent conflict, criticism, or demands from others may make the neuroendocrine and cardiovascular systems more reactive to stress, and such increased reactivity, in turn, may cause negative changes in the brain that impair cognitive functioning (Tun et al., 2013).