Beyond the Lab and Borders: A Systematic Review of Success, Mental Health, and Career Transitions Among International PhD Students in the United States

Abstract Background: International PhD students account for a growing share of U.S. doctoral graduates – over 40% in science and engineering fields as of 2023 [1]– and contribute substantially to research output. Yet they face distinctive structural and psychosocial challenges (e.g. visa restrictions, funding barriers, cultural isolation) that may impact degree completion, well-being, and career outcomes [2,3]. We conducted a systematic review to synthesize recent empirical evidence on how these factors affect international doctoral students’ academic success, mental health, and post-graduation transitions in the U.S. Methods: We systematically searched five databases (Scopus, Web of Science, ERIC, PsycINFO, and ProQuest Dissertations & Theses Global) in late 2024 for peer-reviewed English-language studies (2019– 2025) focusing on international PhD students in U.S. universities [4,5] . Keywords combined terms for international/foreign doctoral students, U.S. context, and outcomes (e.g. “mental health,” “academic success,” “immigration policy,” “career transition”). Two reviewers independently screened titles/abstracts and full texts (using Rayyan) following PRISMA guidelines [6,7]. Data on study design, sample, measures, and findings were extracted. Studies were appraised with standard tools (JBI, CASP, MMAT) but not excluded on quality [8,9]. Because of heterogeneity, we performed a convergent synthesis: quantitative results were summarized descriptively (and meta-analyzed when ≥3 comparable studies, e.g. pooled prevalence of depression) [10], and qualitative findings were integrated into thematic categories through iterative coding. Findings: We identified 1,354 unique records, screened 224 full-text articles, and included 48 empirical studies in the final synthesis [7]. The studies spanned diverse disciplines and methods (25 quantitative, 15 qualitative, 8 mixed methods) [11]. Key findings converged on five interconnected domains: mental health (high levels of anxiety, depression, stress, and burnout among international PhD students), career uncertainty (under-preparedness for non-academic careers and visa-related constraints), academic progression (delays in degree completion and attrition linked to funding and mentorship), supervisory relationships (quality of advising critically shapes satisfaction and persistence), and institutional belonging (sense of inclusion in department/community). For example, multiple studies reported that ~20–25% of international doctoral students met clinical thresholds for depression or anxiety [12,13]. Acculturative stress, visa insecurity, and isolation compounded these mental health burdens [13,14], yet utilization of counseling services remained low due to stigma and lack of culturally-adapted care [15] . Career planning was hampered by rigid immigration rules (OPT deadlines, H-1B caps, green-card backlogs) [16]; faculty and departments often provided little industry-oriented career guidance [17]. Stable funding and effective mentorship were major predictors of timely completion [18]. Financial precarity (especially among those ineligibles for fellowships) and unclear program expectations increased time-to-degree and attrition risk [18]. Likewise, many international students experienced misaligned supervision: advisors often focused on productivity without providing emotional or cultural support [19,20]. Students emphasized that clear communication, consistent feedback, and cultural sensitivity were crucial for effective mentoring [19,20] . Finally, a sense of belonging was uneven: students in inclusive, well-structured environments reported higher engagement and persistence [21], while those in opaque, competitive programs felt alienated. Across studies, the combination of poor mentorship, funding insecurity, and immigration stress translated into compounded disadvantages for international PhDs (e.g. supervisors’ neglect fueling both academic delays and psychological distress [22]). Interpretation: International PhD students are a vital but under-served segment of U.S. graduate education. Their experiences underscore that academic success and well-being are shaped not only by individual effort but by intersecting systemic factors – from visa policy and funding eligibility to departmental culture and supervisory practices. Current graduate structures often fail to address these needs. We conclude that universities and policymakers must undertake systemic reforms: for instance, expanding culturally competent mental health services, integrating visa/immigration support into career advising, and training faculty in intercultural mentorship [23]. Departments should adopt transparent norms, peer mentoring, and inclusion programs to foster belonging. Collectively, these evidence-based interventions are not optional extras but strategic imperatives for sustaining the contributions of international doctoral scholars to U.S. research and innovation [24,25].