# Dynamic Complexity of Positive and Negative Affect in NSSI – A Daily Diary Study

## TL;DR

This study explores how positive and negative emotions fluctuate in individuals with a history of non-suicidal self-injury compared to controls.

## Contribution

The study introduces dynamic complexity as a novel method to analyze affective patterns in non-suicidal self-injury.

## Key findings

- Individuals with NSSI history showed higher dynamic complexity in positive and negative emotions than controls.
- The NSSI group had higher mean levels of positive emotions compared to controls.
- Within-person variation in dynamic complexity explained more variance than group or time differences.

## Abstract

Non-suicidal self-injury (NSSI) is a major health problem. Functionally, it is related to affect instability and increased affective intensity. The role of negative emotions has already been extensively explored, only few studies have focused on positive emotions. The concept of dynamic complexity (DC) is particularly well suited to differentially analyze the dynamics of affect collected by ecological momentary assessment (EMA). This study examines DC of positive and negative emotions in individuals with and without NSSI history in an EMA setting.

Participants from a clinical NSSI group (n = 28) and a comparable clinical non-NSSI control group (n = 33) completed the Positive and Negative Affect Schedule (PANAS) once a day between six to 37 days (M = 15.60, SD = 5.80). DC was calculated for the assessed time-series of daily affect. Additionally, we fitted a linear mixed model to predict positive and negative dynamic complexity with length of stay and group.

Compared to controls, individuals with a history of NSSI showed significantly more positive affect and had significantly higher DC in affect in general. No significant difference for negative affect was found.

Our results suggest that it is important to assess dynamic emotional patterns and to analyze in detail the role of positive and negative affect in individuals with NSSI in order to better understand the complex interplay between the different emotional states and to be able to use it for diagnostic purposes and clinical interventions.

The NSSI group showed a higher DC in positive and negative emotions than clinical controls.The NSSI group showed higher mean levels of positive emotions than clinical controls.Within-person variation in DC explains more variance than survey period or group differences.

The NSSI group showed a higher DC in positive and negative emotions than clinical controls.

The NSSI group showed higher mean levels of positive emotions than clinical controls.

Within-person variation in DC explains more variance than survey period or group differences.