On 2016 Nov 08, Peter Hajek commented:

One problem with interpretation is that in these studies, very few if any people actually stopped smoking. The provision of stop smoking treatments (as opposed to actually stopping smoking) does not seem to undermine concurrent substance use treatments, but the question of whether actually stopping smoking helps with or undermines concurrent efforts to stop using other drugs, and whether sequential treatments yield better results than doing this concurrently, have not been well answered so far.

On 2016 Nov 08, Peter Hajek commented:

One problem with interpretation is that in these studies, very few if any people actually stopped smoking. The provision of stop smoking treatments (as opposed to actually stopping smoking) does not seem to undermine concurrent substance use treatments, but the question of whether actually stopping smoking helps with or undermines concurrent efforts to stop using other drugs, and whether sequential treatments yield better results than doing this concurrently, have not been well answered so far.