Objective <p>Bipolar disorder is a severe and chronic mental illness defined by extreme and debilitating shifts in mood, energy, and activity levels. The World Health Organization has recognized bipolar disorder as a leading cause of disability worldwide. The complex manifestations of the disorder present a profound challenge not only for patients but also for their families, impacting interpersonal relationships, occupational stability, and overall quality of life.</p> Methods <p>In this cross-sectional, correlational study, 80 adults with DSM-5 bipolar disorder and one cohabiting family member each were recruited at an outpatient psychiatric clinic in Maracaibo, Venezuela (May–September 2024). Participants completed a validated 40-item Family Dynamics Scale and the WHOQOL-BREF. Adherence was assessed via a composite index of self-reported missed doses, prescription refill records, and family involvement. Statistical analysis involved descriptive statistics and the Pearson correlation coefficient to assess the relationship between treatment adherence and perceived family functioning.</p> Results <p>This study showed a strong, positive correlation (<i>r</i> = 0.82) between pharmacological treatment adherence and the perception of family functioning. The average adherence rate was 67.25%. Despite significant symptom severity, including episodes lasting over one week (100%) and severe psychotic symptoms (69%), patients reported a moderate-to-high quality of life (mean WHOQOL-BREF score: 78). Family support was a key factor, with 89% of patients reporting effective family involvement in their treatment management.</p> Conclusions <p>High pharmacotherapy adherence correlates with healthier family dynamics. Integrating family-focused educational interventions into standard care could enhance adherence, stability, and quality of life, advocating for a family-centered treatment approach.</p>