In this research study, we are trying to better understand HIV risk, substance use, and challenges with medication adherence in adults. We aim to better understand how decision-making and reward processes in the brain influence health behaviors, including adherence to HIV prevention medication (PrEP). These behaviors are also shaped by individuals’ experiences and daily habits, and we will measure all of these. We also want to see whether we can improve these behaviors using a behavioral program designed to support healthier choices. To do that, we are using a structured approach called Episodic Future Thinking (EFT), which helps individuals focus on future goals and improve decision-making related to their health.

You may be eligible for this study if you meet the following criteria.

Inclusion Criteria

• Adults aged 18–34
• HIV-negative
• Identify as gay, bisexual, or transgender
• Have had condomless anal sex or an STI in the past 3 months
• Own a smartphone
• Fluent in English
• Able to attend study visits

Exclusion Criteria

• Currently receiving treatment for a substance use disorder
• HIV-positive
• Medical or psychiatric conditions that would interfere with participation
• Unable to provide informed consent
• Unable to attend study visits
• Plans that would prevent study completion (e.g., surgery, major medical treatments such as chemotherapy, incarceration, or moving away from San Antonio, Texas)

The entire study lasts about 6 months. Once enrolled, the study involves:

At the study site:
You will complete an initial visit that includes screening and baseline assessments such as questionnaires, interviews, and lab tests (e.g., rapid HIV testing, urine screening for substance use and PrEP adherence). You will also meet with a counselor for study sessions focused on HIV prevention, substance use, and health behaviors.

Follow-up visits:
You will return for additional visits at 1 month, 3 months, and 6 months. These visits include follow-up assessments, counseling sessions, and lab tests to monitor health behaviors and medication adherence. Some participants will also take part in additional sessions using a mobile app to support future goal-setting and decision-making.

From home:
You may be asked to use a mobile app between visits to support your goals and track your progress related to health behaviors.

As a participant, you may receive up to $260 for your time.

There is no cost for you to participate in our research study.