People who read self-help books may be more sensitive to stress and show higher depressive symptoms, according to a new study. The study by researchers, including those from the University of Montreal in Canada, raises doubts about the effectiveness of self-help books.

“Initially, we thought we had observed a difference in participants in terms of personality, sense of control, and self-esteem based on their self-help reading habits,” said Catherine Raymond, a doctoral student at the Institut universitaire en sante mentale de Montreal.

“Our results show that while consumers of certain types of self-help books secrete higher levels of cortisol (a stress hormone) when confronted with stressful situations, consumers of another type of self-help books show higher depressive symptomatology,” she said.