Underutilization of community care services has been described for informal dementia caregivers. Most research has however examined caregivers' access to home or respite care rather than to services for themselves. The aims of this study are: to describe access and retention of informal dementia caregivers in psychosocial interventions; examine the perceived effects of interventions among users and motives for non-use among non-users; and compare caregivers with and without lifetime access and retention in psychosocial interventions across predisposing, enabling and need variables. A cross-sectional study was conducted with 179 Portuguese caregivers, who replied to a web-based survey. Participants were fairly distributed among those who have never (49.7%) and those who have ever accessed (50.3%) psychosocial interventions. Individual psychological support was the most used intervention (32.2%). Caregivers' age, time elapsed since diagnosis and the relationship with the care receiver were associated with lifetime access to various intervention types. Dropout was above 50% for most intervention types, except for psychoeducation (31.8%). Associations were found between a history of dropout/retention and caregivers' education, perceived mental health, and the number of hours spent caring. Most users of psychoeducational interventions (>80%) appraised it as beneficial to learn about the disease, provide quality care and cope with caregiving. Informational barriers were the most reported by non-users of psychoeducational interventions (45.1%). The findings show that dementia caregivers continue facing barriers to use and keep using community services for themselves. The influence of particular predisposing and need variables on access to psychosocial interventions can vary according to intervention types.