Abstract
An association between dizziness symptoms and psychological factors has been hypothesized, but evaluating this through questionnaires alone risks recall bias. We aimed to clarify this relationship using the EMA method to reduce bias. Participants comprised 30 patients (16 with persistent postural perceptual dizziness (PPPD), 14 with the others) aged 20–74 years with functional dizziness symptoms. Participants were sent survey forms at random times for 10 days, 890 hierarchical data were obtained. Survey forms were included the Subjective Dizziness Symptoms (SDS) evaluated as medical condition and the Positive and Negative Affect Schedule assessed as affects. Level 1 model revealed: Positive affect (PA) had a negative fixed effect on SDS in both groups, but the group-mean centering of PA was significant only in the others group. Level 2 model revealed: Negative affect (NA) had a significant fixed effect in both groups; however, the interaction between PA and NA was significant only in the others group. A simple slope analysis of the others group revealed that, in participants with higher NA, reduced momentary SDS was associated with higher PA. Functional dizziness symptoms were more severe when PA was low and NA high. Treatment for functional dizziness pathology could begin with PA.