Antidepressant piperidine derivatives

An antidepressant composition comprising an antidepressant amount of a compound of the formula:

• ##STR24## or a pharmaceutically acceptable acid addition or quaternary ammonium salt thereof, wherein the piperidine ring is substituted in the 3- or 4-position and in which
• Y is --NR.sup.5 --, --O--, or --S--, where R.sup.5 is hydrogen or alkyl of 1 to 6 carbon atoms;
• A is alkylene of 1 to 6 carbon atoms or hydroxyalkylene of 1 to 6 carbon atoms;
• Z is ##STR25## Z.sup.1 is ##STR26## R.sup.1, R.sup.2 and R.sup.3 are, independently, hydrogen, halogen, alkyl of 1 to 6 carbon atoms, alkoxy of 1 to 6 carbon atoms, nitro, amino, alkylamino of 1 to 6 carbon atoms, trifluoromethyl, alkanoylamino of 2 to 6 carbon atoms, hydroxy, or phenylalkoxy of 7 to 12 carbon atoms;
• or
• R.sup.1 and R.sup.2 taken together with adjacent carbon atoms to which they are attached form a six membered carbocyclic ring;
• and
• R.sup.4 is hydrogen or alkyl of 1 to 6 carbon atoms;
• with the proviso that when A is --CH.sub.2 --, R.sup.1 and R.sup.2 are other than nitro;
• and a pharmaceutically acceptable carrier.