The “central” importance of loneliness in mental health: A factor analytic and network psychometric study

Loneliness is associated with undesirable mental health outcomes such as depression and social anxiety. However, the pathways that lead from loneliness to depression and social anxiety or vice versa are unclear. This study aims to answer three questions in relation to this: firstly, is loneliness a distinct construct to social anxiety and depression, secondly, are there transmission pathways connecting to loneliness, and thirdly, what are the influential symptoms that form these transmission pathways? This study employed comprehensive factor and network analyses in a representative, adult UK sample (N= 962, Mean age = 46, females = 492) to try to answer these questions. The network was found to have four dimensions: the mental health constructs depression as one and social anxiety as two, and two for loneliness, isolation and social connectedness. Two major pathways for the transmission of symptoms between loneliness and the mental health constructs were found that were distinct for each of the mental health constructs. The depression-isolation pathway contained a highly influential node that reflected the perceived loss of social connections. The social anxiety-social connectedness pathway was characterised by intimate interaction contexts. The results point towards loneliness being a distinct construct with different symptom activation mechanisms possibly driving comorbidity for different mental health disorders.