1 Centre for Research in Human Development, Department of Psychology, Concordia University, Montréal, QC, H4B 1R6, Canada. florenciatrespalacios@hotmail.com.
2 Centre for Research in Human Development, Department of Psychology, Concordia University, Montréal, QC, H4B 1R6, Canada.
3 Département de Psychiatrie, Université de Montréal, Montréal, Canada.
4 Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.

Background: The offspring of parents with bipolar disorder (OBD) are at higher risk of developing psychopathology than the offspring of parents with no affective disorder (control). In addition to genetic predisposition, childhood adversity and a stressful family environment are important risk factors for the OBD. Protective factors in parents, such as social support and coping strategies, may buffer the effects of stress on at-risk children. This study tested whether parents' social support and coping style attenuated the link between risk status (OBD vs. control) and psychopathology in offspring.

Methods: During offspring's middle childhood, parents underwent a diagnostic interview and completed social support and coping style questionnaires. Sixty-nine OBD (39 female) and 69 control (29 female) offspring between ages 13 and 29 completed a diagnostic interview approximately 10 years later.

Results: Parents' social support satisfaction moderated the link between offspring risk status and their development of substance use disorder (SUD) symptoms (F(1,131) = 5.90, p = .017). Parents' social network size moderated the link between offspring risk status and their development of anxiety and depression symptoms in an unexpected direction (F(1,131) = 5.07, p = .026). No effects of parents' coping style were found.

Conclusions: Among the OBD, having parents with greater social support satisfaction and, unexpectedly, a smaller social network buffered their development of SUD and depression and anxiety symptoms by early adulthood. Parents' social support may thus have a protective function for children in these high-risk families.