Hello! Chronic insomnia, which i understand is in your case, can be difficult to treat in some cases. For the medical treatment tow types of drugs are usually used, short and intermediate acting benzodiazepines and sedating antidepressants. The mos frequent benzodiazepiens used for insomnia are Zolpidem, Zaleplon, Eszopiclone. The use of these drugs should have some precautious, they should be used the lowest effective dose, for a period 2 - 8 weeks, avoid nightly use, avoid using alcohol with these drugs. The antidepressants used more frequently in insomnia are amitriptyline, nortriptyline, mirtazapine, trazodone, doxepin. One group can t substitute the other. They in some cases for a short time can be used combined. So if you re not having any improvement from the use trimipramine, you can t use zopichlone as a substitute. I would suggest to use another antidepressant. Regarding the stopping of trimipramine, as with all antidepressants, it should be slow and steady, the dose will decrease gradually allowing two to six weeks between dose reduction. I would highly suggest to consult your doctor and make the examinations and evaluations if there is something else underlying insomnia and eventually make a detaile plan of the treatment. I hope i have been of help.