Ego defense mechanisms, defined by Freud as unconscious resources used by the ego to reduce conflict between the id and superego, are a reflection of how an individual deals with conflict and stress. Vaillants’ proposed Hierarchy of Defenses states that mature defenses are associated with better adaptive functioning and health, as opposed to immature defense which are correlated negatively with measures of adaptive adult functioning.

This study assesses the prevalence of various ego defense mechanisms employed by medical students of Karachi, which is a group with higher stress levels than the general population.

A questionnaire based cross-sectional study was conducted on 682 students from five major medical colleges of Karachi in November 2006. Ego defense mechanisms were assessed using the Defense Style Questionnaire(DSQ-40) individually and as grouped under Mature, Immature, and Neurotic factors.

Neurotic defenses had a higher mean score(5.62) than Mature(5.60) and Immature(4.78) mechanisms. Immature mechanisms were more commonly employed by males whereas females employed more Neurotic mechanisms than males. Neurotic and Immature defenses were significantly more prevalent in first and second year students. Mature mechanisms were significantly higher in students enrolled in Government colleges than Private institutions (p< 0.05).

Neurotic mechanisms are more commonly encountered than Mature or Immature mechanisms among medical students of Karachi, and this could reflect greater stress levels than the general population. Employment of these mechanisms was associated with female gender, enrollment in a private medical college, and students enrolled in the first 2 years of medical school.