Session-by-session dataset of autonomic and emotional modulation and suicidal ideation in a patient with borderline personality disorder, Brazil, 2025–2026

The dataset was generated from a longitudinal single-case study conducted in Brazil between 2025 and 2026, involving a participant who underwent repeated psychometric and psychophysiological assessments across baseline, treatment-as-usual, and post-intervention phases, as well as session-by-session measurements during intervention. Data generation began with a clinical anamnesis interview aimed at establishing a diagnostic formulation based on the primary complaint, followed by a structured diagnostic assessment using the SCID-5-CV. Outcome variables were collected using validated psychometric instruments assessing suicidal ideation, trauma-related symptoms, dissociation, resilience, alexithymia, quality of life, and emotional symptoms, including the FSII-Br-m, BSI, CD-RISC-10, WHOQOL-Bref, TAS-26, DASS-21, LEC-5, PCL-5, DES-II, and ACE-IQ.Psychophysiological data included heart rate variability (HRV), indexed by RMSSD (in milliseconds), and skin conductance response (SCR), reflecting autonomic nervous system activity. HRV was recorded using a Polar H10 sensor, with data acquisition via the Elite HRV mobile application and subsequent processing and analysis performed using Kubios HRV software. Measurements included five-minute baseline recordings (b), five-minute recordings under controlled breathing conditions (resp), and continuous recordings during assessment and intervention sessions. From these continuous recordings, specific time windows were extracted corresponding to peak parasympathetic activity (pp) and peak sympathetic activation (ps).The dataset is organized in tabular format, with rows representing different clinical and physiological measures and columns corresponding to sequential sessions (e.g., clinical interview, structured assessment, baseline, intervention sessions, and follow-up). Units of measurement vary according to each instrument (e.g., scale scores, milliseconds for RMSSD). Missing data may occur in sessions where specific measures were not collected, and these are represented as blank cells. No known systematic measurement errors were identified; however, physiological signals may be subject to artifacts related to movement or sensor variability, which were minimized during preprocessing. The dataset is provided in standard tabular formats compatible with commonly used statistical software.