I also wonder if there was a certain time in WT history where psychological evaluation was frowned upon.
Yes it was, and not too long ago. It is still frowned upon in some areas, but I don't think it as taboo as it used to be.
"... As a rule, for a Christian to go to a worldly psychiatrist is an admission of defeat. It amounts to 'going down to Egypt for help' - Isaiah 31:1. ...Also, more and more psychiatrists are resorting to hypnosis which is a demonic form of worldly wisdom." (Awake!1960 March 8 p. 27)
Would it be wise for a Christian to consult a mental-health practitioner?
"In some places it has become quite fashionable to seek therapy. In many cases the patient does not have a severe mental disorder but has difficulty coping with some situation in life. However, it is the Bible that gives the most effective help in handling the difficult problems of life. (Psalm 119:28, 143) Through the Bible, Jehovah supplies wisdom, thinking ability, and true knowledge—things that fortify us mentally and emotionally. (Proverbs 2:1-11; Hebrews 13:6) Faithful servants of God may express themselves irrationally at times because of severe inner turmoil. (Job 6:2, 3) James 5:13-16 encourages such ones to call on the elders for help and counsel. A Christian may be spiritually sick, or he may be distressed by an unchangeable circumstance or by oppressive stresses, or he may feel that he is the victim of injustice. (Ecclesiastes 7:7; Isaiah 32:2; 2 Corinthians 12:7-10) Such a person can find help with the elders, who will ‘grease him with oil’—that is, skillfully impart comforting Bible counsel—and also "pray over him." The result? "The prayer of faith will make the indisposed one well, and Jehovah will raise him up [out of his despondency or his feeling of being abandoned by God]."" (w96 9/1 pp. 30-31)
So basically, if you THINK you might be having mental problems, you're probably not. You just need to let the elders lube you up. God help them all!