Extensive evidence indicates that adults with experience of childhood trauma and disorganised attachment are at a higher risk of suffering from depressive symptoms, while at the same time dissociation and mentalisation are very important risk and protective factors in this relation. Although mentalisation and dissociation are mentioned as potential mediators of this relationship, very few studies have analysed the mutual relations between these variables. Bearing in mind the importance of creating more specific and effective ways for dealing with depression, especially within vulnerable groups such as the traumatised, the aim of this research is to examine a serial mediation model in which disorganisation is modelled as effecting a decrease in mentalisation, in turn lead to dissociation, thereby resulting in depressive symptoms. Adult respondents (N = 153) with a history of interpersonal childhood trauma were selected from a larger geographical cluster sample from the general population of Serbia. The respondents filled in a battery of instruments, including The Childhood Traumatic Events Scale, Relationship Questionnaire -CV, Patient Health Questionnaire, Short Scale for the Assessment of Stress-Related Dissociation Symptomatology and the Mentalisation Scale. Our findings suggest that disorganisation has an effect on depression by leading to a decrease in the ability to mentalise, which further triggers dissociation, resulting in depressive symptoms as a final consequence (estimated indirect effect = 0.014, 95 percent CI = 0.005 to 0.026). Additionally, the specific indirect effect involving dissociation as the sole mediator was also significant (estimated indirect effect = 0.058, 95 percent CI = 0.030 to 0.091). Targeting dissociative symptoms in the treatment in patients struggling with depression aftermath of traumatic experience could gain a great benefit for recognition and selection of more adequate treatment strategies.