Drs Ionescu and Cusin Reply

See letter by Apeldoorn et al and article by Ionescu et al

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Drs Ionescu and Cusin Reply

To the Editor: We thank Dr Apeldoorn and colleagues for their interest in our article.

We agree that our small sample size is a limitation, as highlighted in our article.1 This underscores the importance of the pressing need for larger controlled trials on ketamine’s antisuicidal effects.

We would also like to emphasize that, although most of the patients in our study endorsed passive death wishes (as opposed to having suicidal behaviors), our treatment goal is one of zero suicidal thinking. We would argue that any thoughts of death to oneself, including wishing to be dead, are serious medical matters that may require intervention. Indeed, for our study, we excluded patients with suicidal thinking who required immediate inpatient psychiatric care. However, treatment of outpatients with chronic suicidal thoughts and treatment-resistant depression—a common type of patient seen in an outpatient psychiatry office—is of great importance. This is why we chose to study this group. Further research into other populations with suicidal thinking is certainly necessary.

Finally, using a large (N = 133) sample of well-characterized patients with treatment-resistant depression, Ballard and colleagues2 recently suggested that improvements in suicidal ideation after ketamine infusion are related to, but not completely driven by, improvements in depression and anxiety. Our data suggested that decreases in suicidal ideation might be independent of decreases in depression after ketamine at a trend level (P = .05). Given our small sample size, we suggest that further studies are needed on the potential different mechanisms of ketamine’s antidepressant versus antisuicidal actions.

References

1. Ionescu DF, Swee MB, Pavone KJ, et al. Rapid and sustained reductions in current suicidal ideation following repeated doses of intravenous ketamine: secondary analysis of an open-label study. J Clin Psychiatry. 2016;77(6):e719-e725. PubMed doi:10.4088/JCP.15m10056

2. Ballard ED, Ionescu DF, Vande Voort JL, et al. Improvement in suicidal ideation after ketamine infusion: relationship to reductions in depression and anxiety. J Psychiatr Res. 2014;58:161-166. PubMed doi:10.1016/j.jpsychires.2014.07.027

Dawn F. Ionescu, MDa,b

dionescu@partners.org

Cristina Cusin, MDa,b

aDepression Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston

bHarvard Medical School, Boston, Massachusetts

Potential conflicts of interest: None.

Funding/support: None.

J Clin Psychiatry 2017;78(1):e72

https://doi.org/10.4088/JCP.16lr11210a

© Copyright 2017 Physicians Postgraduate Press, Inc.