"i&#039;ve been taking clonazepam 5 mg to 10mg tablets as needed for anxiety and nerve pain for 4 years now, and also have add.  as of lately i&#039;ve noticed that about an hour after taking clonazepam i felt restless and tense, almost jittery and my muscles tightened up and i was wide awake so i basically got 2 hours of sleep at night.  i would say that after long term use, even if it is as needed, clonazepam definitely causes affects of insomnia and muscle stiffness."