Premature babies may have a much higher risk of developing mental health disorders.
That's according to a new study of medical records in Sweden.
Compared to babies born at full term, babies born at less than 32 weeks were seven-times more likely to be hospitalized with bipolar disorder as adults.
Premies were three times more likely to be hospitalized for depression as adults and more than twice as likely for psychosis.
People born between 32 and 36 weeks also suffered from mental health conditions as adults, but with less severity than those born more prematurely.
Experts aren't exactly sure why, but they do say an immature nervous system could play a part.