Insomnia which persists may be due to an underlying psychiatric or medical condition, to side-effects from medication, movement disorders (such as restless legs syndrome), poor sleep hygiene (i.e drinking that second glass of wine whilst watching tv before going to be) or learnt sleep preventing behaviours (intrusive thoughts and worry which prevent sleep).
I admitted a 74 year old gentleman into our sleep lab this week, who told me that he had trouble falling asleep, woke up several times in the night and had difficulty falling back to sleep. Typical complaints of someone suffering from insomnia. When quizzed further, he admitted that this had been the case for the last 20 years. Asked if he could think of a reason for this, he frankly concluded that it was probably due to marriage problems. He felt constantly under stress due to his wife and did not get on with her anymore. He felt he was too old to break-up from her. In fact, the only nights where he did sleep well now, were when she was away on holiday. He had never sought counselling or help regarding this, which was my obvious suggestion to him.
If counselling will help him and his wife remains to be seen. A marriage so unhappy, that it has deprived sleep for 20 years. Truly a sad case of insomnia.