BACKGROUND: Evidence supports the conceptualization of adult attachment as existing along a continuum of attachment security and insecurity; however, ongoing debates persist regarding the use of categorical versus continuous approaches to studying attachment. Attachment data collected from a large community sample of mothers and their offspring in young adulthood were used to examine i) latent classes of adult attachment, ii) associations between mother and offspring attachment, iii) the relationship between adult attachment and mental health symptoms. METHODS: Mothers and offspring were each administered the Attachment Style Questionnaire when offspring were aged 21-years. Latent class analyses (LCA) were performed to examine response patterns across ASQ items. Associations between mothers' and offspring attachment, and correlations between attachment domains and depression/anxiety subscales were examined. RESULTS: LCA identified four latent classes across a continuum of secure and insecure attachment rather than four distinct adult attachment styles. Anxious attachment subscales correlated strongly with depression/anxiety symptoms in both cohorts. Mothers' attachment was significantly but weakly correlated with their young adult offspring attachment. LIMITATIONS: Attachment was measured at one time point and as such, a causal maternal-offspring attachment relationship could not be established. CONCLUSIONS: Findings support a dimensional view of attachment security and insecurity over a four-category model of adult attachment. Attachment correlated with anxiety and depressive symptoms and highlights the importance of considering adult attachment when addressing mental health. There was limited evidence of a relationship between middle aged mothers and their offspring in young adulthood, suggesting other factors influence attachment in adulthood.