Clinical and biological predictors of response to electroconvulsive therapy (ECT): a review.

Electroconvulsive therapy (ECT), developed in the 30's by Bini and Cerletti, remains a key element of the therapeutic armamentarium in psychiatry, particularly for severe and life-threatening psychiatric symptoms. However, despite its well-established clinical efficacy, the prescription of ECT has declined constantly over the years due to concerns over its safety (cognitive side effects) and an increasingly negative public perception. As for other treatments in the field of psychiatry, ECT is well suited to a personalized approach that would increment its efficacy, as well as reducing the impact of side effects. This should be based on the priori identification of sub-populations of patients sharing common clinical and biological features that predict a good response to ECT. In this review we have selectively reviewed the evidence on clinical and biological predictors of ECT response. Clinical features such as an older age, presence of psychotic and melancholic depression, a high severity of suicide behavior, and speed of response, appear to be shared by ECT good responders with depressive symptoms. In mania, a greater severity of the index episode, and a reduction of whole brain cortical blood flow are associated with ECT good response. Biological determinants of ECT response in depressive patients are the presence of pre-treatment hyperconnectivity between key areas of brain circuitry of depression, as well as of reduced glutamine/glutamate levels, particularly in the anterior cingulated cortex (ACC). Furthermore, pre ECT high plasma homovanillic acid (HVA) levels, as well as of tumor necrosis factor (TNF)-α, and low pre-ECT levels of S-100B protein, appear to predict ECT response. Finally, polymorphisms within the genes encoding for the brain-derived neurotrophic factor (BDNF), the dopamine 2 receptor gene (DRD2), the dopamine receptor 3 gene (DRD3), the cathechol-o-methyltransferase (COMT), the serotonin-transporter (5-HTT), the 5-hydroxytryptamine 2A receptor (5-HT2A), and the norepinephrine transporter (NET), appear to predict a good response to ECT. The integration of these data in specific treatment algorithm might facilitate a personalized approach in ECT.

Effectiveness of maintenance electroconvulsive therapy in rapid-cycling bipolar disorder.

OBJECTIVES: : To evaluate the effectiveness of maintenance electroconvulsive therapy (m-ECT) in rapid-cycling (RC) bipolar disorder (BPD) patients. METHODS: : A population sample of 14 patients with BPD (type I or II) and an RC course were treated with m-ECT. Patients had not responded to previous treatments. Sessions of m-ECT were administered monthly and then gradually decreased in frequency upon amelioration of the course. Response to treatment was evaluated as the difference between days of illness before and after the treatment for the same 2 periods in a 2-year time frame. RESULTS: : We treated 14 patients with RC BPD (mean age, 46 years; 71% women; 64% with BPD type I). Mean treatment duration was 21 months. All patients improved during treatment. Eight (58%) did not relapse during the 2-year follow-up period, and 6 (42%) relapsed one time each year. Illness duration decreased 13-fold from 304 to 24 days of illness per year, and illness-free intervals increased from 52 to 334 d/yr (all P < 0.0001). A multivariate analysis showed that the factors independently associated with improvement were male sex, diagnosis of type II BPD, hyperthymic temperament, and younger age. CONCLUSIONS: : Despite patients' clinical severity, we recorded a highly significant reduction of illness morbidity. The m-ECT had a real, long-term prophylactic effect in treating a severe clinical course such as that with rapid cycles. Notwithstanding, our study has to be considered preliminary and carries some limitations, such as its naturalistic design and relatively low number of patients recruited.