A Comparison of Independent Depression and Substance-Induced Depression in Cannabis-, Cocaine-, and Opioid-Dependent Treatment Seekers. - Dakwar, Elias; Nunes, Edward V.; Bisaga, Adam; Carpenter, Kenneth C.; Mariani, John P.; Sullivan, Maria A.; Raby, Wilfrid N.; Levin, Frances R. (American Journal on Addictions, 2011)