A new study published in JAMA Psychiatry examined whether specific developmental trajectories of fasting insulin (FI) levels and body mass index (BMI) from early childhood were longitudinally associated with psychosis and depression in young adults.

This was a prospective study including a population-representative British cohort of 14 975 individuals, aged 1-24 years. Body mass index and FI level data were used to deduce developmental trajectories, and associations with psychosis and depression were assessed. 

The findings showed three distinct trajectories for FI levels and five distinct trajectories for BMI, all of which were differentiated by mid-childhood. The persistently high FI level trajectory was associated with a psychosis at-risk mental state and psychotic disorder but not depression. While a puberty-onset major increase in BMI was associated with depression but not psychosis.

It was inferred that elevated insulin levels in childhood may be associated with psychosis in young adulthood. Moreover, disrupted insulin sensitivity could be a risk factor for the comorbidity of cardiometabolic disorders with psychosis. Meanwhile, puberty-onset major increase in BMI could be a risk factor or risk indicator for adult depression. 

Source: JAMA Psychiatry. 2021 Jan 13;e204180. doi: 10.1001/jamapsychiatry.2020.4180.