Aims and objectivesTo identify illness trajectories in amyotrophic lateral sclerosis by analysing personal, social and functional dimensions related to amyotrophic lateral sclerosis progression. BackgroundPrevious studies have considered some psychological distinct variables that may moderate illness progression, but no research has combined an extensive qualitative understanding of amyotrophic lateral sclerosis patients' psychological characteristics and illness progression. DesignA mixed-methods approach was used to combine quantitative and qualitative measures. Illness progression was assessed through a longitudinal design. MethodsEighteen patients with amyotrophic lateral sclerosis attending a Neurology Department in northern Italy participated in the study. Semi-structured interviews to explore personal experience, and dependency grids to assess the distribution of dependency; ALSFRS-R and neuropsychological screening were, respectively, used to measure physical and cognitive impairment. To assess the progression of the disease, ALSFRS-R was re-administered after 8months and mortality rate was considered. Data were analysed using the grounded theory approach. ResultsIllness progression changed according to the perception of the disease, the trust placed in medical care, self-construction and the distribution of dependency. Based on these categories, cases that had similar experiences were grouped, and four illness trajectories were identified: aggressiveness, threat, constriction and guilt. ConclusionThe findings suggest that it is possible to identify different illness trajectories in amyotrophic lateral sclerosis. Relevance to clinical practicePersonalised intervention strategies may be construed based on the different trajectories identified.