I have been on 15mg Mirt for nearly two years and my anxiety, depression and panic attacks are much improved. However I have severe issues with insomnia and for the first year thought I had found the much longed for answer with this drug and enjoyed a good night's sleep and no after effects. Now, however the sedative effect seems to have worn off and I am no longer sleeping again. Some nights I am awake all night and others I cannot sleep till around 4.00 or 5.00am. Otherwise Mirtazapine has been excellent, no weight gain and no significant drowsiness during the day. The lack of sleeping is now becoming chronic and I don't know whether to get Dr to change the meds or change the dosage( I understand that the lower dose is best for sleep) . Anyone found that it ceases to work? Does it kick back in ever..I am getting desperate! Thanksxxxx