Role of age at onset in the clinical presentation of bipolar disorder in Indian population.

OBJECTIVE

The objective of this study was to determine any association of age at onset (AAO) with clinical presentation of bipolar disorder (BD) and family history of illness.

MATERIALS AND METHODS

A hospital-based cross-sectional observational study was conducted including 162 patients having a diagnosis of BD current episode manic. Individuals were divided into three subgroups according to AAO, i.e., early-onset BD (EOBD) (AAO ≤21 years), intermediate-onset BD (AAO - 22-34 years), and late-onset BD (AAO ≥35 years). The subgroups were compared on clinical variables; items of the Young Mania Rating Scale (YMRS), Hamilton Depression Rating Scale (HAM-D), and Scale for the Assessment of Positive Symptoms (SAPS); and family history of illness.

RESULTS

The early-onset group had significantly more episodes per year than the other groups ( < 0.001). The prevalence of family history of mood disorder was also significantly higher in the early-onset group than the other subgroups. AAO was found to be significantly associated with different items of YMRS, HAM-D, and SAPS. The early-onset group had higher rating on irritability, motor activity-energy, sexual interest, depressed mood, delusions, and thought disorders, whereas the late-onset group had higher rating on elevated mood.

CONCLUSION

EOBD can be considered as a specific phenotype of BD, which is more homogenous, severe, and inheritable form of illness.