Severe Depression Following Recovery From Thrombotic Thrombocytopenic Purpura (TTP)

Recovery from an acute episode of TTP is typically assumed to be complete. However patients from the Oklahoma TTP-HUS Registry have often described persistent problems with memory, concentration, and endurance. Our previous studies have documented long-term deficits in quality-of-life and cognitive functioning. We have also observed an unexpectedly high frequency of severe depression. Therefore we documented the relative frequency of severe depression during long-term follow-up and compared the relative frequency of severe depression in our patients to US and Oklahoma population data.

We included all Oklahoma TTP-HUS Registry patients whose initial episode was associated with severe ADAMTS13 deficiency (<10%), 1995–2010, and who were alive in 2004 when our psychiatric evaluations began. Patients completed the Beck Depression Inventory-II (BDI-II) 1–5 times from 2004–2011. The BDI-II is a self-report measure consisting of 21 items. Scores are interpreted as suggesting no/minimal, mild, moderate or severe depression. In 2011, patients who had BDI-II scores indicating moderate or severe depression on at least 1 evaluation had a structured psychiatric interview to support the diagnosis of depression. In 2012, all patients were asked to complete an 8-item measure, the Patient Health Questionnaire-8 (PHQ-8). The relative frequency of patients whose PHQ-8 scores indicated major depression were compared to the relative frequency of major depression determined by the PHQ-8 in the Oklahoma and US populations in the most recent Behavioral Risk Factor Surveillance System (BRFSS) data, 2006 and 2008.

Of 68 patients who had severe ADAMTS13 deficiency at the time of their initial episode of TTP, 52 were alive in 2004; 47 (90%) were evaluated by the BDI-II. Fifteen (32%) of the 47 patients had scores suggesting severe depression on at least 1 evaluation; 12 were alive in 2011 and 10 (83%) of these 12 patients underwent a structured psychiatric interview; 9 met criteria for a major depressive disorder based on this diagnostic interview. Seven (15%) of the 47 patients had scores indicating only moderate depression; 4 (57%) of these 7 patients underwent a structured psychiatric interview; 1 (25%) met criteria for a major depressive disorder. Thirty-seven (88%) of 42 surviving patients in 2012 were evaluated by the PHQ-8 6.3 years (median) after their initial episode; 7 (18.9%, 95% CI, 8.0–35.2) had scores suggesting major depression, which is significantly greater than the prevalence of major depression in the US (3.4%) and Oklahoma (3.5%). The greater relative frequency of major depression was consistent across demographic subgroups.

The relative frequency of severe depression is increased in patients during long-term follow-up after recovery from TTP. Recognition and appropriate management of this clinically important health problem are critical components of the care of patients who have survived acute episodes of TTP.

Kremer Hovinga:Baxter Healthcare: Consultancy, Research Funding. Terrell:Amgen, Inc.: Consultancy; Baxter, Inc.: Consultancy. George:Alexion, Inc.: Consultancy; Amgen, Inc.: Consultancy, PI for clinical trial involving romiplostim, PI for clinical trial involving romiplostim Other, Research Funding; Baxter, Inc.: Consultancy.