Evaluation of parent bonding style and traumatic experiences in patients with schizophrenia and bipolar disorder: A case-control study.

Background: There is no consensus about the etiology of schizophrenia (SQZ) and bipolar disorder (BD). Both hereditary and environmental factors are recognized, but the importance of variables like the role of parental attachment and trauma is still under research.

Aims: Evaluate and compare the patient-parent bonding and the frequency and severity of various types of trauma in patients with SQZ, BD, and a control group from Primary Health Care.

Method: This study included 50 patients with SQZ and 50 with BD followed at a psychiatric hospital, through a convenience sample. Each participant of the clinical sample was paired with a control with no psychiatric background of the same gender and similar age, from a primary health center. Two scales were applied - Parental Bonding Instrument (PBI) and Childhood Trauma Questionnaire - Short Form (CTQ-SF).

Results: Regarding PBI, there was a higher frequency of the most dysfunctional attachment style (affectionless control), in patients with SQZ and BD, with  < .001 (always), both for the father and the mother. In addition, ideal parenting style (optimal parenting) was significantly more common in control samples, with  = .002 or <.001, both for the father and for the mother. Trauma was more frequent and severe in SQZ and BD than controls, in all evaluated dimensions. Again, differences between groups are obvious, with  = .012 or <.001. Parental bonding style and scores in the care and overprotection dimensions were also correlated. The only parental bonding style in which correlations were found was in affectionless control. Correlations were more common in cases of neglect compared to abuse.

Conclusions: In this research we found important differences in terms of parental attachment and childhood trauma between patients with SQZ and BD, compared with controls of the same gender and age.