The primary purpose of this study is to compare, over 24 months, the time spent with clinically significant mood symptoms (ie, mania, depression), as measured by the Longitudinal Interval Follow-Up Evaluation (LIFE) and the Psychiatric Status Rating Scale (PSR), in offspring of bipolar parents with and without at least mild impairment in psychosocial functioning.

Inclusion Criteria:

• Participants must have at least one parent who meets the criteria for diagnosis of Bipolar I disorder (BD-I) or Bipolar II disorder (BD-II), as confirmed by the Mini International Neuropsychiatric Interview (MINI) administered to the parent. MINI will be administered to parent if the history of BD is endorsed by Family Index of Risk for Mood (FIRM) or other medical information (psychiatrist, medical records). The MINI can be administered to the parent remotely through the telephone or video call if an in-person interview is not feasible due to logistical reasons. A diagnosis Bipolar Disorder Not Otherwise Specified in the parent would not qualify for eligibility
• Participants must be either drug-naive, or on stable treatment for at least 4 weeks.
• Participants (and/or their parents as applicable) must sign an Informed Consent Form (ICF) allowing data collection and source data verification in accordance with local requirements and/or sponsor policy. Adolescents (minors) who in the judgment of the investigator are capable of understanding the nature of the study can be enrolled only after obtaining consent of a legally acceptable representative. Assent must be obtained from any participating adolescents (minors), if applicable
• Participants must be willing and able to complete self-reported assessments via mobile electronic device, and to wear a wrist actigraphy device for the duration of the study

Exclusion Criteria:

• Diagnostic and Statistical Manual of Mental Disorders (DSM) -IV Diagnosis of bipolar I or bipolar II disorder
• DSM-IV Diagnosis of schizophrenia, schizophreniform or schizoaffective disorder
• DSM-IV Diagnosis of neurodevelopmental disorders
• An intelligence quotient (IQ) score less than (<) 80 as determined by Kaufman Brief Intelligence Test (K-BIT)
• Uncorrected hypothyroidism or hyperthyroidism

Offspring of parents with Bipolar Disprder (BD) will be recruited primarily at selected sites which are already conducting research in prodromal BD and have the necessary setup and resources already in place to conduct such a study.