The goal of this study is to explore the role of gender (female/ male) and its contingencies (personality's features and the impact of psychosocial stress factors) in the vulnerability for depression. This study covered a population of twenty men and twenty women, of 35 to 55 years old, diagnosed with Major Depressive Disorder (DSM-IV), followed in outpatient clinical Department of Psychiatry of HUC. Each gender was acceded with NEO- PI-R (personality's five domains) and a comparative analysis was done regarding each item of this scale and its value as a depressive mood element inductor. In parallel it is also analysed the impact of psychosocial stress factors (health, love, social and professional lives) in the perpetuation (recurrence) of the depressive episodes, emphasizing the most constant and relevant for each sex.