To Örebro University

OBJECTIVE: Although electroconvulsive therapy (ECT) is anti-suicidal, it is not known whether the presence of suicidal ideation (SI) at baseline predicts response and remission after ECT. The aim of the study was to analyze the impact of baseline SI on response and remission following ECT treatment in a large sample of patients with depression and to assess SI before and after ECT.

METHODS: This population-based register study used data from the Swedish National Quality Register for ECT and the Swedish Patient Register. Patients aged 18 years or older who had received ECT for a unipolar or bipolar depressive episode between 2011 and 2018 were included in the study. SI was defined as a score of ≥ 4 on the last item of the Montgomery-Åsberg Depression Rating Scale - Self Assessment (MADRS-S). Using a logistic regression model, SI at baseline was used to predict response and remission following ECT, while controlling for depression severity, psychotic symptoms, presence of a comorbid personality disorder, age, sex, electrode position, unipolar or bipolar disorder, and number of previous suicide attempts at baseline.

RESULTS: In patients who exhibited SI at baseline, 53.7% (N = 632) of cases showed a response to ECT, whereas 68.4% (N = 690) of patients without SI showed a response. In addition, 27.2% (N = 320) of cases with SI achieved remission, whereas 48.5% (N = 489) of cases without SI achieved remission. The odds of achieving response and remission for patients with SI were 0.75 and 0.58 times, respectively, those for patients without SI. Of the 1178 patients with pre-treatment SI, 75.64% (N = 891) exhibited no SI at the end of treatment. Moreover, in this subgroup, the presence of a personality disorder, higher MADRS-S-score, and younger age were associated with persistent SI.

CONCLUSION: The presence of SI was associated with lower ECT response and remission rates. Nevertheless, depressive symptoms and SI were reduced in a large proportion of patients across both patient groups. Clinicians should be aware of the lower likelihood of achieving a successful outcome following ECT in younger patients who present with a non-psychotic depressive episode, SI, and (suspected) personality disorders. More research is warranted regarding if these patients can achieve similar or better results with other treatments.