The Collaborative International Dictionary of English v.0.48:

Psychologic \Psy`cho*log"ic\, Psychological \Psy`cho*log"ic*al\,
   a. [Cf. F. psychologique.]
   Of or pertaining to psychology. See Note under Psychic. --
   Psy`cho*log"ic*al*ly, adv.
   [1913 Webster]

WordNet (r) 3.0 (2006):

psychological
    adj 1: mental or emotional as opposed to physical in nature;
           "give psychological support"; "psychological warfare"
    2: of or relating to or determined by psychology; "psychological
       theories"

Moby Thesaurus II by Grady Ward, 1.0:

39 Moby Thesaurus words for "psychological":
   cerebral, cognitive, conceptive, conceptual, endopsychic,
   functional, intellectual, intelligent, internal, mental,
   neuropsychiatric, noetic, noological, philosophical, phrenic,
   psychiatric, psychic, psychical, psychobiological, psychodynamic,
   psychogenic, psychologic, psychoneurological, psychopathic,
   psychopathological, psychophysical, psychophysiological,
   psychosexual, psychosocial, psychosomatic, psychotic, rational,
   reasoning, spiritual, subconscious, subjective, subliminal,
   thinking, unconscious