The withdrawal effect is nasty, it should be tapered off gradually to get rid off it to minimize such withdrawals effects.
How many mg was he taking for
how long?Do I understand right if you said he used to take or is taking 10 pills a day or is 10mg a day? I don't think there is such low dose as 10 mg, I heard of 50mg minimum, so if it is 10 pills a day no matter how many mg each is is a strong dependence he is on, the more mg the worse it is.