A new pair of studies from MIT Media Lab and OpenAI found that those who use the chatbot most heavily also experience the most loneliness. The catch-22: it’s unclear whether this is caused by the chatbot itself or if lonely individuals are simply more likely to seek out emotional bonds.

Researchers analyzed millions of interactions and found that only a small number of users rely on ChatGPT for emotional support—but those who do are among its heaviest users. The MIT study found that higher daily usage of ChatGPT “correlated with higher loneliness, dependence, and problematic use, and lower socialization.” Since loneliness is a tricky feeling to quantify, researchers said they measured both users’ subjective feelings of loneliness and their actual levels of socialization.

The studies also found that heavy users were more likely to consider the chatbot a “friend” or attribute human-like emotions to it. Those engaging in “personal” conversations with the chatbot reported the highest levels of loneliness. If they set the chatbot’s voice mode to the opposite gender, those levels were even higher.