The goal of this clinical trial is to identify the specific characteristics (phenotypes) that may be useful to help select the right medication for weight loss, and to study the effect of individualized guided medication in patients with bipolar disorder ages 18-65. The main questions it aims to answer are:
* Can the investigators compare the distribution of obesity characteristics (hungry brain, hungry gut, emotional hunger) between bipolar patients and non-bipolar participants (comparing from IRB #24-002375)?
* Can the investigators evaluate the feasibility of anti-obesity medication (AOM) in patients with bipolar disorder?
Participation will last for about 20 weeks and includes 8 in-person study visits, up to 11 phone call visits, and 13 virtual group therapy sessions. The first visit lasts about 2 hours and includes going over the informed consent form, a diagnostic interview to confirm diagnosis, gathering vital signs, mood questionnaires, an ECG, a blood draw, and urine drug and pregnancy tests (if applicable). The second visit lasts about 6-7 hours and involves multiple procedures and completing questionnaires to determine which study drug would allow participants to lose weight most effectively. At the third visit, participants will be assigned to take one of three FDA approved medications for weight loss: Semaglutide (Wegovy®), Naltrexone/Bupropion (Contrave®), or Phentermine/Topiramate (Qsymia®). It is possible that participants could be assigned to a group that receives no study medication. All participants will be enrolled in a 12-week virtual group therapy program targeted for weight loss. On this third visit the investigators will also gather vital signs, and participants will give a sample of blood. After the third visit, participants will come in for study visits every 4 weeks for 20 weeks (5 visits) to assess medication adherence, vitals, and answer questions about mood and eating (participants will also give a sample of blood at the 8-week and 20-week visits). For participants assigned to a study medication, the study team will call every week for the first 2 months (excluding in-person visit weeks) to assess mood and safety. After the first 2 months, the study team will call the participant every two weeks in between in-person visits. Participants will be compensated for time spent in this study. Participants assigned to a study medication will also be given the option to participate in the open-label phase of the study, which involves 3 follow-up visits (weeks 24, 36, and 48) over 7 months after the 20-week trial. During this phase, participants can continue to take the medication through their clinical care provider.