Most parents of multiple children say they want to time the births of their children close together in order for them to have a built-in best friend for life. But according to a recent study out of The Ohio State University, depending on how many children parents have and how close they are in age, that could affect their mental health poorly when they’re teens

Science Daily reported, Doug Downey, lead author of the study and professor of sociology at The Ohio State University said in the study, “The details of the pattern vary depending on factors such as the spacing of sibling ages and the age of the siblings … but the fact that the overall pattern was found in both countries is striking.” 

This “pattern” included some interesting similarities even spanning two different countries. “In China, teens with no siblings showed the best mental health, while in the United States, those with no or one sibling had similar mental health,” Science Daily reported.

The reasons poor mental health occurs in teens in this situation makes total sense—and some could argue it’s basically common sense. Downey said it comes down to parental resources. 

“If you think of parental resources like a pie, one child means that they get all the pie — all the attention and resources of the parents,” he said. “But when you add more siblings, each child gets fewer resources and attention from the parents, and that may have an impact on their mental health.”

The teens’ mental health also comes down to socioeconomics. The less children to care for financially, the more of an advantage those families have socioeconomically. So of course these children will potentially be less stressed and have more opportunities available to them based on their socioeconomic status. 

The study did not take into consideration the quality of the sibling’s relationships, which is important to note. Obviously if the siblings have a wonderful, supportive and nurturing relationship, that would affect their mental health in a positive way.

Another plus side, multiple siblings close in age actually is beneficial for when they’re young. “While this study shows a negative impact of siblings, other research has shown that having more brothers and sisters is associated with better social skills among kindergarteners and a lower likelihood of divorce among adults,” per Science Daily.

So not all hope is lost if you already have several children close in age. According to Science Daily, Downey said in the study, “Previous work in the field had revealed a mixed picture of positives and negatives for children with more siblings, adding that the latest results ‘were not a given.’”