When one spouse has Alzheimer's disease (AD), marital interactions tend to decline. Findings from this study suggest that level of spousal interactions influence longitudinal outcomes for afflicted spouses. Thirty AD spouses and their spouse caregivers were assessed at baseline (time 1) and two years later (time 2). Continued in-home care at time 2 is predicted by high levels of positive spousal interactions, high caregiver commitment, good caregiver health, and shorter time as caregiver (all assessed at time 1). The same variables but in an inverse relationship predict which AD spouses are deceased at time 2. Nursing home placement is predicted by AD spouses' higher educational level, unhappy marital relationships, and low caregiver commitment. Afflicted spouses' cognitive and functional impairment levels, their physical health and depression do not predict outcomes. A theoretical explanation is developed drawing on Riegel's dialectical theory of human development and Bowlby's attachment theory. It is suggested that interactions between spouses are crucial for afflicted spouses' survival.