If replicated, a personalized risk assessment risk calculator would provide a useful tool to predict personalized risk of conversion from subsyndromal mania to bipolar disorder (BD) I/II and inform individualized interventions and research, according to a recent study. 140 youth with BD not otherwise specified (BP-NOS; aged 6–17 years) followed through the Course and Outcome of Bipolar Youth (COBY) study with at least 1 follow-up assessment before conversion to BD-I/II were included. Youths were assessed on average every 7 months using standard instruments. Risk predictors were used to build a 5-year risk calculator. External validation was performed using an independent sample of 58 youths with BD-NOS recruited from the Pittsburgh Bipolar Offspring Study. They found:

• 75(53.6%) COBY youths with BD-NOS converted to BD-I/II, of which 57 (76.0%) converted within 5 years.
• Earlier-onset BD-NOS, familial hypomania/mania, and high mania, anxiety, and mood lability symptoms were important predictors of conversion.
• The calculator showed excellent consistency between the predicted and observed risks of conversion, good discrimination between converters and non-converters (area under the curve 0.71), and a proportionally increasing rate of converters at each successive risk class.