Several psychological variables have been identified that, when present, are risk factors for the development of non-suicidal self-harm. These variables include dysfunctional personality traits , specifically unstable personalities with high emotional reactivity, a tendency towards impulsive behaviors, or a tendency to develop excessively subjective or egocentric viewpoints, etc.

Dysfunctional personality traits, in general, refer to a persistent pattern of internal experience and behavior that deviates markedly from the individual's cultural expectations. This pattern manifests in the areas of cognition, affect, interpersonal functioning, and impulse control. In adolescence, personality problems can be difficult to diagnose and require the intervention of a clinical specialist, since personality is still forming and structuring during this period, and adolescent crises themselves can lead to non-pathological personality changes that could be mistaken for dysfunctional traits.