(S (S (NP (BASENP (DT A) (JJ new) (NN study)) (PP (IN by) (NP (BASENP (NNP Duke) (NNP University)) (PP (IN in) (BASENP (DT the) (NNP US)))))) (VP (VBZ suggests) (SBAR (S (NP (BASENP (JJ depressed) (NNS adolescents)) (SBAR (WHNP (WP who)) (S (VP (VP (VBP respond) (PP (TO to) (BASENP (NN treatment)))) (PP (IN within) (BASENP (NN twelve) (NNS weeks))))))) (VP (VP (VBP are) (PP (IN at) (NP (BASENP (DT a) (VBN reduced) (NN risk)) (PP (IN of) (BASENP (NN drug) (NN abuse)))))) (PP (ADVP (RBR later)) (PP (IN in) (BASENP (PRPD their) (NNS lives))))))))) (PERIOD .))