Long-Term Course of Loneliness in Psychotic Disorders

Among individuals with psychotic disorders, loneliness is prevalent, cross-sectionally associated with symptom severity, and frequently reported to be a major source of distress. Due to limited longitudinal evidence, the course of loneliness in psychosis remains unclear, as is its direction of effect with symptomatology.

We modelled trajectories of loneliness across 25 years within the Suffolk County Mental Health Project, a cohort enrolled at first admission for psychosis (n = 552) and compared prevalence with a matched sample of never-psychotic adults from the same zip codes (n = 257). Then, we used random intercept cross-lagged panel modelling to estimate associations of loneliness with positive and negative symptoms across 5 assessments of the clinical sample.

Loneliness decreased gradually over time, with prevalence declining from 62% at 6 months after admission to 51% at 25 years (fixed effect of time: P < .001). Still, loneliness's prevalence at 25 years significantly exceeded that of the comparison group (51% vs. 28%, P < .001). Loneliness was greater in males and in individuals diagnosed with schizophrenia. Moderate to strong associations were observed between loneliness and avolition (β = .70, P < .001), inexpressivity (β = .44, P = .002), and reality distortion (β = .44, P = .03) symptoms. Within-person longitudinal analyses found that increasing loneliness did not predict worsening of symptoms or vice versa (β = -.04 to .04).

We found that subjective loneliness was most prevalent early in the illness course among individuals with psychosis, and that individuals with more severe psychotic disorder were lonelier. These associations persisted over years and were not affected by symptom waxing and waning.