Personality Disorders: A preface.

Personality disorders (PDs) are complex psychiatric conditions marked by persistent maladaptive patterns of cognition, emotion, and behaviour. This Special Issue of Neuropharmacology compiles cutting-edge research and reviews exploring the neurobiological, psychological, and therapeutic dimensions of PDs. Contributions span diverse topics, including neurobiological mechanisms, hypothesis for novel treatments, gene-environment interactions, and immune-metabolic influences. Key findings include the role of fatty acid amide hydrolase (FAAH) in aggression in borderline personality disorder (BPD), excitation/inhibition imbalances in antisocial personality disorder (ASPD), and the potential of psychedelics and gut-microbiota modulation as therapeutic interventions. Additionally, research highlights the interplay between genetic vulnerabilities (e.g., genes affecting serotonergic/dopaminergic pathways) and environmental factors (e.g., childhood trauma) in shaping PD phenotypes. This collection underscores the need for precision medicine approaches, integrating biomarkers and targeted therapies to improve clinical outcomes. By bridging preclinical and clinical insights, this Special Issue advances our understanding of PDs and paves the way for innovative treatments.