Fraser 1980.

Methods	Allocation: Randomised controlled trial, randomisation procedure not described and allocation concealment unclear; Duration: not specified; patient and outcome assessor blinding seems appropriate; no follow‐up period; Intention‐to‐treat analysis not mentioned, possible 4 patients dropped‐out, authors seem to have used an end‐point analysis;
Participants	Diagnosis: Depressive illness, based on Feigner criteria; Age 64 ‐ 86 years; N = 33, 5 participatns dropped‐out; Sex: 8 M, 25 F; Inclusion criteria: depression of a least a month duration, dementia was not an exclusion criterium, other inclusion criteria not specified.
Interventions	Unilateral versus bilateral ECT; no information is provided on the adequacy of seizures or the method by which seizures were induced; unilateral ECT n = 13 bilateral ECT n = 16
Outcomes	Mood change: Hamilton Rating Scale (HAM‐D) and the Nursus' Observation scale for Inpatient evaluation; Cognitive side‐effects: the Wechsler Memory Scale Other side‐effects by questionnaire
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Unclear risk	B ‐ Unclear