The role of basic psychological needs in the network structure connecting persistent physical symptoms and suicidal thoughts in early adulthood.

Suicidal ideation—defined as thoughts about ending one’s life—remains one of the most distressing and complex phenomena in mental health research. Its prevalence is alarmingly high among young adults, a group that also frequently reports experiencing Persistent Physical Symptoms (PPS)—bodily complaints that fall outside conventional diagnostic categories. An increasing number of studies suggest a potential link between PPS and suicidal ideation; however, the mechanisms underlying this co-occurrence remain poorly understood, particularly within the Polish context. One promising explanatory framework is the frustration or unmet satisfaction of basic psychological needs—autonomy, competence, and relatedness—as described in Self-Determination Theory, which has been associated with deteriorating mental health and suicidality. Despite its relevance, research exploring how these needs intersect with the experience of PPS and suicidal ideation in early adulthood remains scarce in Poland. To address this gap, the current project adopts a convergent parallel mixed methods design within a pragmatic research orientation. The study aims to: (1) estimate the prevalence and severity of PPS among Polish women and men aged 18–29, and examine gender differences as well as how symptom intensity co-varies with quality of life, satisfaction of basic psychological needs, depressive symptoms, hopelessness, and suicidal ideation; (2) explore associations between these variables using network analysis, with particular attention to the configuration of co-occurring factors and the role of basic psychological needs; and (3) examine the narratives of young adults experiencing PPS, with a focus on how their accounts reflect the broader context of daily functioning, the psychological impact of symptoms, and coping, as well as the relevance of autonomy, competence, and relatedness. The quantitative strand will involve a cross-sectional, self-report survey administered online via a national research panel and analyzed statistically. The parallel, independent qualitative component will consist of remote individual interviews analyzed using a reflexive thematic approach. Together, these findings aim to deepen theoretical understanding and provide an empirically grounded foundation for further research and for developing psychological support that is contextually informed and responsive to the lived realities of young adults with PPS.