OBJECTIVES: The Clinical Care GroupsTM (CCG) software transforms fragmented claims data into episodes of medical conditions. The results of health care claims data grouped by CCG indicate that many SSRI claims are not grouped into a medically related episode. Our objective is to describe the clinical profiles of SSRI users who have ungrouped SSRI claim(s). METHODS: A random sample (N=1,400,000) of individuals was generated for the study from de-identified health care claims data of a large U. S. health plan. Individuals who had been continuously enrolled in the health plan for the 24-month full period between April 1, 1999 and March 30, 2001 were eligible for the study. Those with at least 1 SSRI pharmacy claim were selected (N=74,739). An equal number of individuals without SSRI claims were also selected. Medical and pharmacy claims data were run through CCG version 3.1 and generated the following groups of individuals: Group A consisting of non-SSRI users; Group B consisting of individuals with grouped SSRI claims; and Group C consisting of individuals with at least one ungrouped SSRI claim. RESULTS: The average age in each group was: A - 36, B - 42, and C - 45. Prevalence of SSRI indicated disorders in each group were: A - 54, B - 724, and C - 56 (cases/1,000 members). On average, individuals in group C had 7 SSRI prescriptions whereas individuals in group B had 9. The average health care utilization for each group was: A - $4051, B - $9574, and C - $7920. The average number of unique providers visited for each group was: A - 9.5, B - 16.5, and C - 13.4. Of the grouped SSRI prescriptions, psychiatrists prescribed 25.0% whereas only 7.6% of the ungrouped SSRI were prescribed by psychiatrists. CONCLUSION: Significant differences exist between individuals with and without ungrouped SSRI prescriptions and may illuminate the cause of ungrouped SSRI prescriptions.