The impact of loneliness and social relationship dissatisfaction on clinical and functional outcomes in Dutch mental health service users.

The relationship between reduced social connectedness and mental health outcomes is increasingly acknowledged. Yet, relatively little is known about how two crucial subjective aspects of social disconnectedness - loneliness and social relationship dissatisfaction (SRD) - are related to clinical and functional recovery. This cohort study aimed to investigate the associations of loneliness and SRD with various mental health outcomes among 15,512 outpatients from a Dutch mental health service. Demographics and data on loneliness, SRD, symptomatic distress, suicidal ideation, and role functioning, as well as treatment duration, and mortality, were collected. The study analyzed the associations between these factors overall and by diagnostic group, gender, and age, using cross-sectional and longitudinal regression, while controlling for relevant covariates. Findings revealed significant, independent, associations between loneliness, SRD, symptomatic distress, and role functioning across different diagnostic groups. Particularly strong associations were noted in bipolar and psychosis-related disorders. Gender did not significantly influence the strength of associations. In older patients, lower levels of loneliness and SRD were observed, but the impact on clinical and functional outcomes was consistent across ages. Higher loneliness and SRD were associated with longer treatment durations, regardless of age, gender or diagnosis. This study indicates the wide-reaching effects of perceived social disconnectedness on recovery and emphasizes interventions targeting loneliness and SRD to enhance outcomes.