It’s no surprise that dogs benefit people’s mental health. In a paper publishing in the Cell Press journal iScience on December 3, researchers point to a reason as to why: dogs prompt changes in the collection of microbes that live in and on our bodies, resulting in an increase in mental health. 

A new study of 2,000 U.S. adults shows dark web users report much higher rates of depression, paranoia, suicidal thoughts, self-injury and digital self-harm than surface web users. People with suicidal thoughts were nearly three times more likely to use the dark web, while those engaging in self-injury or digital self-harm were up to five and 19 times more likely, respectively. Researchers suggest dark web use may reflect underlying mental health struggles and urge professionals to reach vulnerable users in these hidden spaces.