Back ground: De spite its well-established ef fi cacy and its in creas ing use, elec tro con vul sive ther apy (ECT) re mains a con tro versial treat ment. Lack of clar ity in the is sues re lated to its use in spe cial pa tient popu la t ions (for ex am ple, in chil dren populations, children, adolescents, pregnancy, postpartum, elderly, frail elderly, medically-ill, brain tumours A l though the use of elec tro con vul sive ther apy (ECT) for treat ment of se vere de pres sion and other men tal dis orders has been well es tab lished (1,2), it con tin ues to cre ate con tro versy (3,4). It is there fore vi tally im por tant for cli nicians to be aware of the avail able evi dence for ECT use in spe cial and vul ner able popu la tions. De spite the ex po nen tial growth in the un der stand ing of ECT neu ro bi ol ogy (5,6), its mode of ac tion is still un clear. This ar ti cle criti cally ex am ines the rele vant lit era ture and pro vides clini cal guide lines for the use of ECT in spe cial pa tient popu la tions. These con sist of the child, ado les cent, and eld erly popu la tions; preg nant and postpar tum pa tients; and those with con cur rent medi cal con ditions who re quire ECT. This pa per re fers the reader to the Ameri can Psy chi at ric As so cia tion (APA) task force re port on the prac tice of ECT (sec ond edi tion), re leased in Janu ary 2001, for spe cific in di ca tions and con tra in di ca tions (7).