Background: In recent decades, doctoral education has undergone a profound transformation. As a result, PhD students have become an increasingly vulnerable population, facing greater risk of mental health problems than the general population. A particularly important subgroup comprises PhD students in medicine and health sciences, who often combine doctoral training with clinical work. Their dual roles expose them to additional pressures, with an increased risk of burnout. Given that their context differs considerably from the typical university environment, in this systematic review, we aim to synthesize the current evidence on burnout, impostor syndrome, and research engagement, along with related indicators of psychological distress, among PhD students in medicine and health sciences, as well as identify key risk and protective factors and highlight gaps for future research. Methods: A systematic literature search was conducted in March 2026 across the Web of Science, Scopus, and Ovid MEDLINE databases. Following a screening process based on PRISMA guidelines, 27 studies were included; due to substantial heterogeneity, findings were synthesized narratively. Results: Psychological difficulties appeared to be more strongly associated with institutional factors rather than personal traits. Burnout was highly prevalent and linked to professional isolation and poor relationships with supervisors. Impostor syndrome emerged as a recurrent theme in qualitative accounts, though it was formally assessed with a validated instrument in only one study. Moreover, research engagement did not appear to protect students from burnout. Conclusion: Burnout and psychological distress are widespread among PhD students in medicine and health sciences, and impostor feelings emerged as a recurrent theme, although formally measured in only one study. These findings highlight the need for structural and institutional changes rather than relying solely on individual psychological support.

Background/Objectives: Various psychological and sociodemographic factors are strongly associated with shopping addiction in different populations. To date, the relationships between these variables have not been fully clarified. European data indicate a rise in shopping addiction among adults over the past two decades, but population-based epidemiological studies in Central and Eastern Europe, including Croatia, remain scarce. This study was conducted to examine the prevalence of shopping addiction and its related factors in Croatian adults. Methods: A cross-sectional online survey was conducted, with data collected via Google Forms from February to April 2024. An anonymous questionnaire covering sociodemographic data, the Bergen Shopping Addiction Scale (BSAS), and the Rosenberg Self-Esteem Scale (RSES) was self-administered by participants recruited using snowball sampling of Croatian adults. Results: The study included 715 participants from all Croatian regions. In the present sample, 14.3% of participants met the BSAS ≥ 12 cutoff, indicating probable and problematic shopping addiction. The BSAS score was significantly higher among females (p = 0.008), high school and university students (p = 0.048), and young adults aged 18–25 years (p = 0.042). Most participants reported average self-esteem (68.0%), while 31.2% and 0.8% had low and high self-esteem, respectively. BSAS scores correlated positively with RSES scores (ρ = 0.225; p < 0.001), while age was negatively correlated with both BSAS (ρ = −0.147; p < 0.001) and RSES (ρ = −0.356; p < 0.001) scores. After controlling for age and sex, the correlation between BSAS and RSES scores remained significant: partial rho = 0.103 and p = 0.006. Conclusions: Shopping addiction was prevalent in the studied population and was associated with specific sociodemographic characteristics and self-esteem levels, highlighting the need for targeted preventive strategies and further research into its underlying mechanisms.