Electroencephalographic and cardiovascular markers of vulnerability within families of suicidal adolescents: A pilot study.

Suicide, self-injury, and predisposing vulnerabilities aggregate in families. Those at greatest risk often show deficits in two biologically-mediated domains: behavioral control and emotion regulation. This pilot study explored electroencephalographic and cardiovascular indices of self-regulation among typical and suicidal adolescents (n = 30/group) and biological family members (mothers, fathers, and siblings). We measured event-related potentials during a flanker task designed to evoke impulsive responding and respiratory sinus arrhythmia (RSA) at rest and during social rejection. Multilevel models indicate control families' RSA was unaffected by social rejection (slope = 0.136, p = .097, d = 0.09), whereas clinical families demonstrated RSA withdrawal (slope = -0.191, p = .036, d = -0.13). Clinical families displayed weaker positive voltage (Pe) deflections following behavioral errors relative to controls (coefficient = -2.723, p = .017, d = -0.45), indicating risk for compromised cognitive control. Thus, families with suicidal adolescents showed autonomic and central nervous system differences in biological markers associated with suicide risk.