Longitudinal dream-content shift and void-like dissociative phenomenology around outpatient ketamine infusions in chronic low back pain: a case report

BACKGROUND: Altered-state phenomenology around ketamine may relate to longer-term changes in imaginal processes, but observations across routine care are scarce. We report an educational case focusing on pre-defined dream motifs over time, without making treatment efficacy claims. CASE PRESENTATION: A 48-year-old Japanese man with severe chronic primary low back pain reported dreams during insight-oriented psychotherapy from 2009 to 2025; over 360 narratives were contemporaneously documented. In 2014, he received five low-dose outpatient intravenous ketamine infusions (15 mg; 0.23 mg/kg; first 20 min, then 30 min; no premedication) and described a void-like dissociative state during the first session. Using a pre-specified codebook, two raters (treating clinician and external psychiatrist) independently coded an ID-based, period-stratified random subset of 50 dreams after re-ordering and masking of period labels for three primary motifs (obstruction, fear, anger) plus a descriptive social-interaction/role-completion motif. Obstruction decreased from pre- to post-ketamine periods in both raters (treating clinician: 6/9 vs 4/30; external psychiatrist: 6/9 vs 7/30). In the double-labelled subset, the social-interaction/role-completion motif was labelled more often post- than pre-ketamine by both raters (2/9 pre; 10/30 and 11/30 post). CONCLUSIONS: Across the observation window that included outpatient ketamine infusions in 2014, dream content shifted from recurrent obstruction toward imagery of movement, interpersonal engagement, and everyday role completion (illustrated by selected de-identified dream narratives; Table 5). These single-patient, hypothesis-generating observations describe ketamine-associated void-like phenomenology and longitudinal dream-content change without making efficacy claims. In insight-oriented outpatient ketamine care, clinicians may prepare patients for possible dissociative/dream-like experiences, invite brief narrative documentation, and offer post-session integration while maintaining standard physiological monitoring.