Motivation in schizophrenia: a theory-driven approach using time-series network analysis

Motivational negative symptoms are an important obstacle to the daily functioning of individuals with schizophrenia. A better understanding of associated processes would help to identify targets for interventions. We used Experience Sampling Method (ESM) to assess the daily cognitive, behavioural and emotional/hedonic processes identified in a redefined theoretical model of motivation in schizophrenia. Further, we applied multilevel network analysis to explore in a preliminary way the potential causal factors that may influence the daily course of motivation. Using a 14-day paradigm ESM in 7 participants with schizophrenia spectrum disorders (276 observations), we examined the interplay between the processes derived from the proposed model. We estimated both contemporaneous and temporal networks using multilevel vector autoregressive analyses for time-series. The contemporaneous network showed that motivation was central and strongly related to levels of energy and (self-)confidence. The temporal network showed that savouring processes (i.e. reminiscence and projection into the future) were the most influential and had an impact on later motivation, mood, effort, energy, (self-)confidence, and discouraging beliefs. These findings provide preliminary evidence in favour of the motivational model presented in this study, shedding new light on the understanding of motivation in schizophrenia and specifically identifying energy levels, savouring processes and confidence as likely beneficial targets for interventions.