Thiochroman compounds

A method of treating a mammal afflicted with depression comprising the step of administering to the said mammal an amount of a compound selected from those of Formula (I) as follows:

• ##STR62## in which:
• R.sub.1 represents a group of formula (B):
• ##STR63## in which R.sub.2 is a group selected from:
• --R'.sub.2 --, wherein R'.sub.2 represents a group --(CH.sub.2).sub.n -- or ##STR64## wherein n is 1 to 6, inclusive, R'.sub.2 being unsubstituted or substituted in the alkylene moiety by lower alkyl, aryl or aryl-lower alkyl,
• and ##STR65## wherein p is 1, 2, or 3 and R.sub.b represents a radical selected from hydroxy, lower alkoxy, lower alkylcarbonyloxy, aryloxy, and aryl-lower alkoxy,
• R.sub.3 and R.sub.4, together with the nitrogen atom carrying them, form:
• an unsubstituted or substituted piperazine, with the proviso that, when R.sub.2 represents a group ##STR66## R.sub.3 and R.sub.4 may not form, together with the nitrogen atom carrying them, a piperazine group substituted at the 4-position by diphenylmethyl unsubstituted or substituted in the phenyl nuclei by one or more radicals selected from halogen, lower alkyl, lower alkoxy, and trifluoromethyl,
• wherein, unless indicated otherwise:
• the expression "substituted" associated with the term "piperazine" indicates that the piperazine is substituted by one or more radicals selected from:
• groups --(CH.sub.2).sub.n' --E--, ##STR67## and ##STR68## wherein n' is 0 or 1 to 4 inclusive and E represents a radical selected from phenyl, benzhydryl, pyrimidinyl, and dicycloalkyl-lower alkyl, it being possible for the group E to be unsubstituted or substituted by one or more groups selected from halogen, lower alkyl, lower alkoxy, and trifluoromethyl,
• the term "cycloalkyl" represents a cyclic group having 3 to 8 carbon atoms inclusive,
• the term "acyl" represents a lower alkylcarbonyl, arylcarbonyl or aryl-lower alkylcarbonyl group,
• the term "aryl" means a phenyl or naphthyl group,
• and the terms "lower alkyl" and "lower alkoxy" indicate linear or branched groups containing 1 to 6 carbon atoms inclusive, an optical isomer, in pure form or in the form of a mixture, and an addition salt thereof with a pharmaceutically-acceptable acid or base, which is effective for alleviation of said disorder.