Family History Linked to ECT Use and New Series in Depression

Family History Links to Higher Electroconvulsive Therapy Rates

Patients with major depressive disorder (MDD) who have a family history of severe mental disorders (SMDs) are more likely to undergo electroconvulsive therapy (ECT) than those without such a history, according to a nationwide study in Denmark published October 28 in the Journal of Affective Disorders.

The study, led by Frederikke Gronemann of Bispebjerg-Frederiksberg Hospital, found that 27.3% of patients who initiated ECT had a familial history of SMD, compared with 24.3% of matched MDD patients who did not receive the treatment. This 3-percentage-point difference was statistically significant (P = .01).

Researchers analyzed data from 34,890 patients, comparing 5,870 who started ECT against 29,020 age- and sex-matched individuals who did not. The definition of familial SMD included any diagnosis of MDD, bipolar disorder, or non-affective psychotic disorders in a parent, sibling, or half-sibling.

Long-Term ECT Recurrence Risks

Among patients who received ECT, a family history of SMDs was associated with about a 40% higher likelihood of starting a new ECT series between two and five years after their initial treatment. The study noted an adjusted hazard ratio of 1.39 for this specific timeframe.

Researchers observed no significant difference in the risk of starting a new ECT series within the first two years following the initial treatment. While the study tracked outcomes such as psychiatric readmission and suicidal behavior, the results indicated that patients with and without a familial history of SMDs showed similar levels of medication use, treatment resistance, and comorbidity in the five years leading up to their first ECT session.

Clinical Implications for Prediction Models

The authors suggest that clinicians should prioritize recording data on familial SMDs when assessing patients for ECT. They noted that these findings indicate such data should be included in clinical and scientific prediction models of ECT response.

Study Defines Severe Mental Disorder and Limits Findings

What defines a severe mental disorder in this study?
Researchers defined familial SMD as the presence of a diagnosis of major depressive disorder, bipolar disorder, or non-affective psychotic disorders in a parent, sibling, or half-sibling before the patient’s ECT treatment.

Are these findings applicable to all patients with depression?
No. The study was limited to patients diagnosed with major depressive disorder in Denmark, where ECT is often utilized earlier in the treatment process than in other regions. Additionally, the observational nature of the study means that causal conclusions cannot be drawn.

Did family history affect treatment resistance before ECT?
The study found no significant differences in pre-ECT treatment resistance—defined as the administration of three or more consecutive antidepressant treatments in the five years before the first ECT session—between those with and without a familial history of SMDs.