A growing body of research suggests that momentary assessment technologies that sample experiences in the context of daily life constitute a useful and productive approach in the study of behavioural phenotypes and a powerful addition to mainstream cross-sectional research paradigms. Momentary assessment strategies for psychopathology are described, together with a comprehensive review of research findings illustrating the added value of daily life research for the study of (1) phenomenology, (2) aetiology, (3) psychological models, (4) biological mechanisms, (5) treatment and (6) gene-environment interactions in psychopathology. Overall, this review shows that variability over time and dynamic patterns of reactivity to the environment are essential features of psychopathological experiences that need to be captured for a better understanding of their phenomenology and underlying mechanisms. The Experience Sampling Method (ESM) allows us to capture the film rather than a snapshot of daily life reality of patients, fuelling new research into the gene-environment-experience interplay underlying psychopathology and its treatment.

OBJECTIVES. The evidence to date for a causal role of emotions in the generation of paranoid symptoms is scarce, mainly because of a lack of studies investigating the longitudinal association between emotional processes and paranoia. The primary aim of this study was to investigate whether momentary emotional experiences (anxiety, depression, anger/irritability) and self-esteem predicted the onset and duration of a paranoid episode. We also studied whether levels of emotional experiences and self-esteem were respectively higher and lower during a paranoid episode. DESIGN. A 1-week, prospective momentary assessment study. METHODS. Data were collected using the experience sampling method, a structured self-assessment diary technique. The sample consisted of 158 individuals who ranged across the paranoia continuum. Participants with a psychotic disorder were recruited from in-patient and out-patient mental health services. Participants without psychotic disorder were sampled from the general population. RESULTS. Specific aspects of emotional experience were implicated in the onset and persistence of paranoid episodes. Both an increase in anxiety and a decrease in self-esteem predicted the onset of paranoid episodes. Cross-sectionally, paranoid episodes were associated with high levels of all negative emotions and low level of self-esteem. Initial intensity of paranoia and depression was associated with longer, and anger/irritability with shorter duration of paranoid episodes. CONCLUSIONS. Paranoid delusionality is driven by negative emotions and reductions in self-esteem, rather than serving an immediate defensive function against these emotions and low self-esteem. Clinicians need to be aware of the central role of emotion-related processes and especially self-esteem in paranoid thinking.

This study revealed no evidence for a generalized hedonic deficit in patients with psychotic spectrum disorders. Lower rather than higher levels of negative symptoms were associated with a pattern of emotional processing which was different from healthy controls.