Re: Dad has thyroid problem?
Yes, it is VERY POSSIBLE to have thyroid problems despite "normal" test results. Part of the problem is what the labs define as "normal." Most healthy people with no symptoms whatsoever of thyroid disease have a TSH of about 1.0. However, most labs use ranges anywhere from .3 to 5.5 to define as normal TSH. Furthermore, most doctors don't even test Free T3 and Free T4 or do thyroid antibody testing. When they test for all of these they get a clearer picture of what is going on. Try to get your dad to get copies of all of his results, and you can post the numbers here. Then some very knowledgable people can help you make sense of the results.
Many doctors just don't seem to understand that a number in the "normal" reference range may not be "normal" for a particular person. An example of this would be to say that adults have a normal shoe size of 5-13. Well, if you give me any shoe within that range, it does not mean that it will fit my foot! Actually, I could have very severe foot, leg, knee, and back pain by wearing a shoe that is only 1/2 size too big or small for me. However, using the same methodology that most doctors use in evaluating thyroid function, a doctor would listen to my complaints about foot pain, etc., and then look at my shoe size. He would then tell me that my shoe is a "normal" shoe size for adults, so all of my symptoms must be from something else, or they all are in my head! If I merely changed my shoes to a more comfortable size for me, though, all of my painful symptoms would disappear. This example is intended to show you how it can be similar with thyroid problems.
I can relate very much with your dad. I, too, was on antidepressants for about 10 years or so. I tried many medications for depression, and none seemed to help. My psychiatrist was perplexed because nothing seemed to help me. I, too, had shock treatment, and that did not help, either. He and at least one other doctor suspected thyroid problems, but they tested my thyroid (I don't know what specific tests they did at that time), and they came back "normal." I assumed he was right, but now years later, I have discovered that "normal" was not "normal" for me. I sat down and wrote down a medical history of myself going back as far as I could remember. Symptoms that I did not even relate with each other now began to make sense. I had nearly every single symptom of hypothyroidism which are too numerous to list here (although not every person has every symptom). I made an appointment with a doctor who was recommended on a website for top thyroid doctors in the country (do a google search, then you should be able to find doctors listed for every state, and even a few foreign countries). I showed him my medical history that I had written, and he said that it looked that I have been hypothyroid all of my life since I was about six or seven years old! Unfortunately, it went undiagnosed all these years. The only thing that doctors seemed to see was fatigue and depression--which are both major symptoms of hypothyroidism--and they prescribed antidepressants, shock treatment, etc. It is very common for people with thyroid problems not to respond well to antidepressants until their thyroid problems are addressed and treated.
I am not sure what the symptom of being hot would indicate. People with hypothyroidism are typically cold a lot, at least in their hands and feet. I am very uncomfortable when the weather is hot and humid outside, though. Perhaps being hot might be a symptom of hyperthyroidism (the opposite of hypothyroidism). I am pretty sure that depression and fatigue is a symptom of hypo as well as hyperthyroid. However, some people who are hypothyroid actually have symptoms of being hyper, and vice versa.
Again, get the test results and post them here, and people will help you interpret them. Have the TSH, Free t3, free t4 and thyroid antibody testing done. Oh, it seems that many people have better luck with holistic MD's or DO's over regular conventional doctors--including endocrinologists. Sometimes even the doctors that are suppposed to specialize in thyroid problems (endocrinologists) get so focused on magic numbers, that they ignore all the patients symptoms. I hope you find the answers which you are searching for, and I hope your dad will feel better soon. By the way, a good book about thyroid problems and how it relates to depression is called The Thyroid Solution by Ridha Arem.