Transcranial sonography of the brainstem raphe: A rapid tool to assess the long-term risk of violent suicidal behavior in patients with major depression

To assess the relationship between ultrasonographic changes in midbrain structures and subsequent violent suicidal behavior. We conducted a retrospective analysis of a previously reported cohort of 46 patients (36 women; age 54.9 ± 11.7 years) with major depression who had been prospectively observed over a ten-year period to assess the risk of developing Parkinson's disease. At study entry, all patients underwent transcranial B-mode sonography to grade the echogenicity of the midbrain raphe and substantia nigra. The outcome measure was the first occurrence of violent suicidal behavior, i.e. a serious suicide attempt or completed suicide. At baseline, four patients were found to have grade 1 raphe echogenicity (invisible), 23 had grade 2 (weakly echogenic), and 19 had normal grade 3 (strongly echogenic). The visually graded echogenicity correlated well with the digitally analyzed echo-intensity ( p < 0.001). Three (75%) patients with echogenicity grade 1 subsequently attempted or completed suicide, as did five (22%) with grade 2, but none with grade 3 (Kaplan-Meier analysis, log-rank test, p < 0.001). The latency period did not differ between echogenicity grade 1 and 2 (34.7 ± 30.9 vs. 22.6 ± 19.7 months, p = 0.59). Overall, patients with reduced raphe echogenicity were less likely to be free of subsequent violent suicidal behavior (3 years: RR, 0.78; 95% CI, 0.64–0.95; p = 0.034; 10 years: 0.70; 0.55–0.90; p = 0.014). No sex differences were found. Echogenicity of the substantia nigra did not improve the prediction of suicidal behavior. Reduced echogenicity of the midbrain raphe indicates an increased risk of subsequent violent suicidal behavior in patients with major depression. • First study of transcranial sonography findings for predicting suicidal behavior. • In 59% of the patients with major depression, the midbrain raphe echo was reduced. • A normal raphe echo predicted 10 years of freedom from violent suicidal behavior. • The lower the raphe echo score, the higher the risk of subsequent suicide attempt. • Substantia nigra echogenicity did not improve the prediction of suicidal behavior.