Abstract Introduction Family members of intensive care unit (ICU) patients are at increased risk of experiencing sleep disturbances, which in turn can exacerbate symptoms of anxiety and depression. However, little is known about how sociocultural determinants influence their predisposition to sleep disturbances, and how such sleep disturbances contribute to symptoms of anxiety and depression across the trajectory of the patient’s ICU stay. Therefore, we sought to: 1) identify individual and interpersonal sociocultural predictors of sleep disturbance symptoms, and 2) describe the influence of select sociocultural determinants and sleep disturbances on subsequent symptoms of anxiety and depression. Methods Using a repeated-measures, correlational design, we recruited family members of incapacitated, mechanically ventilated patients within four adult intensive care units at a tertiary medical center in northeast Ohio. We collected baseline data (T1) after obtaining informed consent and seven (T2) days post-baseline. We measured individual and interpersonal sociocultural determinants, as well as symptoms of sleep disturbance, anxiety, and depression with self-report instruments. To test our aims, we used step-wise linear regression. Results For aim 1 (N = 30), participants who were female, non-white, married, and had prior healthcare decision-making experience reported more severe sleep disturbance symptoms (R2 = .69, F(11,18) = 3.59, p = .008). For aim 2 (n = 20), the aforementioned determinants and T1 sleep disturbance scores significantly predicted T2 anxiety (R2 = .62, F(5,14) = 4.61, p = .01) and depression (R2 = .65, F(5,14) = 5.24, p = .006) severity. None of the predictors were statistically significant for the full anxiety model; notably, the effects of gender and prior healthcare decision-making experience were statistically significant until T1 sleep disturbance was inserted in the model. T1 sleep disturbance scores were the only statistically significant predictor in the full depression model. Conclusion We provide preliminary evidence that sleep disturbances among family members of ICU patient may contribute to the severity of depressive symptoms in family members of ICU patients. We encourage future researchers to replicate and expand upon these findings to understand the development of sleep disparities in this vulnerable population. Support (If Any) Sayre Memorial Fund; Midwest Nursing Research Society; NCATS (1KL2TR002547)