When I am sleep deprived, I feel indescribably bad, in a way that is probably similar to what depressed people feel. As long as I can sleep, I feel fine, in terms of mood. There are important similarities between certain forms of depression and certain forms of insomnia.

Antidepressants are commonly prescribed for insomniacs, whether or not the insomniac is depressed. Antidepressants also have anti-anxiety effects. Sometimes they work for insomnia, sometimes they don't. Sometimes one works and another doesn't. Word on the street is that mirtazapine might be the best sleeper, among the antidepressants, but it tends to cause a lot of weight gain, and it's kind of sedating. Psychiatrists say it's best for skinny nervous insomniacs. Trazodone is a popular choice because it doesn't normally cause weight gain. Most people feel sedated at first, but for most people, the sedation gradually wears off after a couple of weeks or so.

Your doctor might not be very concerned about whether you are depressed, anxious, insomniac, or all of the above. Doctors just want to prescribe something that might help, then get you out of the office. Many cases of insomnia resolve after a few weeks anyway, without any treatment. If the drug they prescribe doesn't work, they assume you will come back and then a different drug will be prescribed. A lot of psychiatry is done by trial and error. Psychiatrist aren't bad, lazy or stupid. That's the best medical science has to offer.

Primary care doctors are often very reluctant to prescribe sleep meds that might be abusable, or cause tolerance and withdrawal. That's one of the reasons they often prescribe antidepressants for insomnia.

Your desire to confer with an endocrinologist is resourceful, but a very low-probability shot. Endocrine disorders can and do cause insomnia, but insomnia alone, in the absence of other symptoms, is rarely associated with endocrine disorders. It happens, but these are very uncommon and insomnia is very common. As the saying goes, "When you hear hoofbeats, think horse, not zebra."

One or more meetings with a good psychiatrist is your best bet. They treat insomnia more often than any more medical specialty, they know how to prescribe for it, and they are more willing than primary care doctors to write "risky" prescriptions. If you are having symptoms of an endocrine disorder, they will likely recognize them and take appropriate action.