Background: Most psychotropic medications that are effective in the treatment of Bipolar Disorder (BD) are associated with endocrine-metabolic changes (EMCs). To date, there is no long-term study in BD that has examined specifically the association of inflammation with EMCs in BD. Specific aims: 1) to identify predictors of EMCs among adolescents and adults with BD who are being started on a medication ; 2) to compare change in EMCs in youth and adults treated for BD; 3) to measure change in EMCs associated with use of different medications for BD. Research Design: Participants: 30 adolescents (14-18 years old) with BD and 30 adults (19-65 years old) with BD. Measures: Blood levels of biomarkers that are associated with EMCs will be measured.

Inclusion Criteria:

1. Provision of written informed consent
2. Diagnosis of BD type I, II, or NOS as determined by DSM-IV diagnostic criteria (confirmed using SCID or K-SADS)
3. Both females and males, age14 to 65 years
4. Decision by physician and patient to initiate pharmacotherapy with a traditional mood stabilizer or atypical antipsychotic
5. Able to understand and comply with requirements of the study
6. Proficient in English.

Exclusion Criteria:

1. A primary psychiatric disorder other than bipolar disorder I, II or NOS (comorbid Axis I or II disorders are permitted, as long as clinician judges that bipolar disorder is the primary condition)
2. Initiation of an antipsychotic, mood stabilizer or other medication with known endocrine-metabolic effects within 4 weeks prior to baseline visit
3. Patients who, in the investigators opinion, are unlikely to adhere to pharmacotherapy for at least 4 weeks after baseline visit
4. Significant medical condition that would contraindicate the use of mood stabilizers or atypical antipsychotics
5. Patients who are receiving pharmacological treatment for diabetes mellitus (DM), hyperlipidemia, or obesity
6. Acute or chronic medical illness (e.g. urinary tract infection, bronchitis, rheumatoid arthritis) that, as judged by the investigator, would significantly alter inflammatory, metabolic, or endocrine indices
7. Screening bloodwork that identifies any other clinically significant deviation from the reference range in clinical laboratory test results, as judged by the investigator.

Thirty adolescent participants with BD (type I, II, or not otherwise specified), and 30 adult participants with BD will be enrolled. Participants with BD will be recruited from the Youth and Adult Mood Disorder Clinics. Psychiatry Division staff will identify patients who meet the study criteria during weekly treatment team meetings. New referrals will also be screened to identify potential participants.