(S (S (BASENP (JJ Related) (NNS studies)) (VP (VBP have) (VP (VBN shown) (SBAR (IN that) (S (BASENP (NN quality) (NNS relationships)) (VP (VBP stimulate) (BASENP (ADJP (JJ mental) (CC and) (JJ physical)) (NN health)))))))) (PERIOD .))