OBJECTIVE: A quantitative study of shifts in states of mind was conducted to demonstrate a clinically useful mode of observation. This mode categorizes observations of a patient's mental state into well- modulated, overmodulated, undermodulated, and shimmering patterns. METHOD: The authors used reliable systems for scoring a patient's state of mind on videotapes of all sessions of her brief psychotherapy and, using separate procedures, scored the topics of discourse. These data were then examined by means of a lagged log-linear sequential analysis for patterns of shifts from one state to another and for concurrent shifts in topics. RESULTS: The findings indicated nonrandom shifts in state. Patterns of shifting from a well-modulated state to alternative states and back again were overrepresented. Such shifts were related to conflictual topics of discourse. CONCLUSIONS: Observing such shifts in mental state may help psychotherapists to formulate the contents of conflict and also to make technical interventions to stabilize optimal states for doing the work of psychotherapy.Abstract Teaser