From biomarkers to care: integrating biology and clinical translation in psychiatry

The quest for reliable biomarkers remains one of the most ambitious and elusive goals of psychiatry. Despite decades of research and major societal investment, only a few candidate biomarkers have progressed beyond internal validation, and even fewer have demonstrated clinical utility¹. This translational gap reflects both the biological complexity of mental disorders and the methodological challenges of linking laboratory, neuroimaging, and other biomarker-derived measures to real-world clinical outcomes. Progress will depend on integrative approaches that combine neuroimaging, cognition, inflammation, and metabolism within longitudinal and mechanistically informed frameworks. The studies featured in this issue of the Spanish Journal of Psychiatry and Mental Health exemplify this multidimensional vision, spanning from neurocognitive and neuroimaging markers to systemic inflammation, metabolic dysfunction, and evidence-based prevention strategies.

Together, these contributions offer a panoramic view of psychiatry as an integrative science, connecting neurobiology, behaviour, and prevention, and pointing toward a future in which biomarker discovery and clinical application evolve hand in hand.

Neural and cognitive biomarkers: mapping the architecture of dysfunction

Cognitive dysfunction represents a core and functionally disabling feature of psychotic disorders, with meta-analytic evidence showing that both neurocognition and social cognition are strongly associated with real-world functioning². Notably, such deficits are already detectable in individuals at clinical high risk for psychosis, supporting their role as potential detection and prognostic biomarkers³.

Yorca-Ruiz et al.⁴ advance this perspective by examining processing speed as a potential cognitive endophenotype for schizophrenia. By dissecting motor and cognitive components of processing speed in first-episode psychosis and their first-degree relatives, they reveal deficits that extend beyond clinical status and appear early in life. The presence of such impairments in unaffected relatives supports processing speed as a candidate early biomarker of vulnerability. Recognizing and targeting processing speed in both assessment and treatment could enable more precise preventive and cognitive-remediation strategies, thereby improving functionality and quality of life.

Corponi et al.⁵ further bridge clinical and neurocognitive dimensions in a large sample of patients with acute schizophrenia. Using a data-driven clustering of PANSS dimensions, the authors identified three clinical profiles. The largest subgroup—characterized by prominent negative and disorganization symptoms—displayed the most pronounced deficits on the Frontal Assessment Battery, a brief measure of frontal-executive functioning that assesses conceptualization, mental flexibility, motor programming, inhibitory control, and environmental autonomy. The strongest associations involved Positive and Negative Syndrome Scale (PANSS) items N5 (difficulties in abstract thinking), N6 (alogia), and G10 (disorientation), underscoring the close interplay between negative, cognitive, and frontal-executive dysfunction. These findings reinforce the view that the “core” of schizophrenia may lie in shared impairments across abstraction, verbal fluency, and executive control—functions that critically depend on prefrontal integrity.

Pérez-Rando et al.⁶ analyse hippocampal and amygdalar subfields in patients with schizophrenia with and without persistent auditory hallucinations. Rather than relying on global volumetric measures, they demonstrate that structural alterations are confined to specific subregions, including the right fimbria, which was reduced in both patient groups. In contrast, reductions in the hippocampal tail, dentate gyrus, and left accessory basal nucleus of the amygdala appeared only in patients with chronic auditory hallucinations. These results highlight the importance of subfield-level analyses in revealing distinct neurobiological signatures within schizophrenia and suggest that patients with enduring hallucinations may represent a specific structural phenotype within the disorder.

Chavarría-Elizondo et al.⁷ bridge the domains of late-life affective and cognitive disorders by identifying a shared pattern of reduced dorsal anterior cingulate cortex activation during attentional target detection in both amnestic mild cognitive impairment and late-life major depression. This convergent hypofunction supports the hypothesis of common neurobiological substrates linking mood and cognitive decline in aging, potentially reflecting early dysfunction within the salience or executive-control networks. Beyond its mechanistic relevance, the study illustrates how functional neuroimaging biomarkers may refine differential diagnosis and guide targeted interventions in elderly populations at risk for Alzheimer's disease or depression-related cognitive impairment.

Together, these four studies trace a continuum from early cognitive vulnerability to structural and functional brain alterations in chronic and late-life conditions, highlighting how neurocognitive and neuroimaging biomarkers can illuminate the developmental and degenerative trajectories of psychiatric illness.

Systemic and inflammatory biomarkers: connecting body and brain

Beyond the central nervous system, several articles in this issue expand the field toward systemic biology, focusing on inflammation, metabolism, and their cognitive and behavioural correlates. Increasing evidence indicates that low-grade systemic inflammation is linked to cognitive dysfunction, negative symptoms, and poorer functional outcomes across severe mental disorders, reinforcing the concept of psychoneuroimmunology as a key dimension in translational psychiatry⁸. Understanding these interactions between peripheral and central processes is essential to move from descriptive associations to mechanistic, treatment-relevant insights.

Sánchez-Ortí et al.⁹ extend the evidence linking obesity and type 2 diabetes—both increasingly prevalent among individuals with severe mental disorders—to neurocognitive and functional decline. Their longitudinal data suggest that adiposity-related inflammatory and oxidative mechanisms may mediate the association between metabolic dysregulation and cognitive impairment across schizophrenia, bipolar disorder, and major depression. These findings reinforce the importance of proactive management of metabolic risk in psychiatric populations, not merely to prevent cardiovascular disease but also to preserve brain health. In this context, incretin receptor agonists such as GLP-1 and GIP analogues have attracted growing attention as mechanistically informed therapeutics with neuroprotective, pro-neurogenic, and cognitive-enhancing potential across psychiatric and neurodegenerative disorders¹⁰. Evaluating their role in patients with severe mental illness represents a promising avenue for future translational research.

Anmella et al.¹¹ describe a multicentre Spanish study addressing the microbiota–gut–brain axis in schizophrenia. Although primarily a protocol paper, it underscores the growing need to integrate peripheral inflammation, intestinal permeability, and microbiome composition into our models of psychiatric disease. By systematically collecting biological, cognitive, and lifestyle data across several participating centres, this project lays the groundwork for future studies capable of disentangling how low-grade systemic inflammation and gut dysbiosis contribute to symptom burden and metabolic comorbidity. It exemplifies how psychiatry is increasingly compelled to look beyond the brain—toward the immune, endocrine, and metabolic systems that shape mental health.

Paniagua et al.¹² further explore the immune interface by analyzing blood-cell-based inflammatory ratios in a large transdiagnostic sample including major depression, bipolar disorder, and schizophrenia. While not designed to replicate a specific prior study, their results expand current knowledge by revealing a sex-specific reduction of the monocyte-to-lymphocyte ratio (MLR) in women with depression and bipolar disorder compared with healthy controls. This finding highlights the importance of incorporating sex as a biological variable in psychiatric biomarker research—a crucial step toward personalized interpretation of immune–metabolic alterations.

In a concise but insightful Letter to the Editor, Jarratt-Barnham et al.¹³ examine the interplay between reward sensitivity, anhedonia, and body-mass index (BMI) in treatment-resistant schizophrenia. Although anhedonia itself showed no direct association with task performance, individuals with higher BMI displayed greater responsiveness to increasing rewards, suggesting preserved motivational drive toward high-reward stimuli. While preliminary, this work extends to chronic schizophrenia earlier observations from first-episode psychosis, highlighting subtle alterations in the reward–metabolic interface and the behavioural pathways through which metabolic dysregulation may emerge in severe mental illness.

Together, these studies situate inflammation and metabolism at the crossroads between brain and body, showing how psychiatric disorders can no longer be understood—or treated—in isolation from systemic physiology.

From discovery to implementation: integrating biological insight and patient safety

As psychiatry advances toward mechanistic and biomarker-based understanding, the translation of scientific knowledge into effective clinical practice becomes equally crucial. The biological sophistication of modern psychiatry must be matched by organizational and preventive sophistication in how we deliver care. Translational psychiatry, in its broadest sense, therefore extends from molecules and circuits to clinical pathways and safety frameworks that strengthen the effectiveness and safety of mental health care.

Within this perspective, Lengvenyte et al.¹⁴ provide a European Delphi-based consensus outlining 43 recommendations for the assessment, management, and post-discharge care of individuals in suicidal crisis. Designed for clinicians across emergency and mental health services, these guidelines emphasize comprehensive evaluation, patient safety, engagement, and continuity of care. Beyond their methodological rigor, the authors stress the importance of large-scale, sustained implementation, supported by professional training and ongoing outcome evaluation. This initiative exemplifies how the translation of evidence into practice remains a cornerstone of psychiatry's social mission—bridging scientific progress with humane, safety-oriented care.

Conclusion: integration as the future of psychiatry

Taken together, the studies and guidelines featured in this issue reflect the dual nature of contemporary psychiatry: deeply biological yet unavoidably clinical and preventive. Scientific discovery gains meaning only when translated into safer, more effective, and compassionate care. The shift toward biomarkers is not merely technological; it represents a conceptual evolution from symptom-based classification to mechanism-based understanding. Yet, as the Delphi consensus reminds us, biological insight must coexist with structured, patient-centered clinical frameworks.

The future of psychiatry will depend on its ability to integrate mechanistic knowledge with humane and preventive care, ensuring that advances in biomarker discovery translate into better outcomes for patients and society.

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[37159365,37159365,31415864].