A coated electrode for use in implantable medical devices for short-term and long-term implantation in the human body, the coated electrode comprising an electrochemically deposited polymeric coating on an electrically conductive substrate of an electrode, the polymeric coating comprising an electrochemical polymerization reaction product of a polymerization mixture comprising: a conductive monomer or a conductive polymer; and a polyanionic counterion component comprising either: (a) a block copolymer, wherein the block copolymer comprises: two or more styrenic blocks independently comprise polystyrene, poly(t-butyl styrene), polymethyl styrene, poly amino styrene, poly carboxylic acid styrene, or a mixture or copolymer thereof; and one or more elastomeric blocks independently comprise polyethylene, polybutylene, polybutadiene, polyisopropene, polyisobutylene, or a mixture or copolymer thereof; wherein from about 10 to 100 mol% of the repeat units of the two or more styrenic blocks are functionalized with a negatively charged functional group; or (b) a random copolymer, wherein the random copolymer comprises: styrenic repeat units comprising styrene, t-butyl styrene, methyl styrene, a carboxylic acid-functionalized styrene, an amine-functionalized styrene, or a mixture thereof; and elastomeric repeat units comprising polyethylene, polybutylene, polybutadiene, polyisopropene, polyisobutylene, or a mixture thereof; wherein from about 10 to 100 mol% of the repeat units are functionalized with a negatively charged functional group. a conductive monomer or a conductive polymer; and a polyanionic counterion component comprising either: (a) a block copolymer, wherein the block copolymer comprises: two or more styrenic blocks independently comprise polystyrene, poly(t-butyl styrene), polymethyl styrene, poly amino styrene, poly carboxylic acid styrene, or a mixture or copolymer thereof; and one or more elastomeric blocks independently comprise polyethylene, polybutylene, polybutadiene, polyisopropene, polyisobutylene, or a mixture or copolymer thereof; wherein from about 10 to 100 mol% of the repeat units of the two or more styrenic blocks are functionalized with a negatively charged functional group; or (b) a random copolymer, wherein the random copolymer comprises: styrenic repeat units comprising styrene, t-butyl styrene, methyl styrene, a carboxylic acid-functionalized styrene, an amine-functionalized styrene, or a mixture thereof; and elastomeric repeat units comprising polyethylene, polybutylene, polybutadiene, polyisopropene, polyisobutylene, or a mixture thereof; wherein from about 10 to 100 mol% of the repeat units are functionalized with a negatively charged functional group. (a) a block copolymer, wherein the block copolymer comprises: two or more styrenic blocks independently comprise polystyrene, poly(t-butyl styrene), polymethyl styrene, poly amino styrene, poly carboxylic acid styrene, or a mixture or copolymer thereof; and one or more elastomeric blocks independently comprise polyethylene, polybutylene, polybutadiene, polyisopropene, polyisobutylene, or a mixture or copolymer thereof; wherein from about 10 to 100 mol% of the repeat units of the two or more styrenic blocks are functionalized with a negatively charged functional group; or two or more styrenic blocks independently comprise polystyrene, poly(t-butyl styrene), polymethyl styrene, poly amino styrene, poly carboxylic acid styrene, or a mixture or copolymer thereof; and one or more elastomeric blocks independently comprise polyethylene, polybutylene, polybutadiene, polyisopropene, polyisobutylene, or a mixture or copolymer thereof; wherein from about 10 to 100 mol% of the repeat units of the two or more styrenic blocks are functionalized with a negatively charged functional group; or (b) a random copolymer, wherein the random copolymer comprises: styrenic repeat units comprising styrene, t-butyl styrene, methyl styrene, a carboxylic acid-functionalized styrene, an amine-functionalized styrene, or a mixture thereof; and elastomeric repeat units comprising polyethylene, polybutylene, polybutadiene, polyisopropene, polyisobutylene, or a mixture thereof; wherein from about 10 to 100 mol% of the repeat units are functionalized with a negatively charged functional group. styrenic repeat units comprising styrene, t-butyl styrene, methyl styrene, a carboxylic acid-functionalized styrene, an amine-functionalized styrene, or a mixture thereof; and elastomeric repeat units comprising polyethylene, polybutylene, polybutadiene, polyisopropene, polyisobutylene, or a mixture thereof; wherein from about 10 to 100 mol% of the repeat units are functionalized with a negatively charged functional group.