The Qtree package is "a LaTeX package for drawing tree diagrams." Is it possible to draw simple graph-like diagrams with it, similar to the one depicted below? If not, should I resort to TikZ-qtree?

The Qtree package is "a LaTeX package for drawing tree diagrams." Is it possible to draw simple graph-like diagrams with it, similar to the one depicted below? If not, should I resort to TikZ-qtree?

Here's one solution.
\documentclass{article}
\usepackage{tikz-qtree}
\begin{document}
\begin{tikzpicture}[sibling distance=1cm, every node/.style={font=\sffamily}]
\Tree [.PSPACE
[.PP
[.BQP
[.BPP \edge[white]; {} \edge; \node[xshift=2cm] (P) {P}; ] ]
[.\node (NP) {NP}; ]]]
\draw (P.north) -- (NP.south);
\end{tikzpicture}
\end{document}
Update
I've changed the method of moving the P node so that it is centred correctly. (Output image has been put in an \fbox to show the image edges.)

\edge[white]; command hides the edge, it prevents the diagram from correctly being centered on the page.
– Sadeq Dousti
Aug 13 '11 at 00:27
\phantom{\hspace{4cm}} (leaving just empty braces) makes the positioning a whole lot better, though it's still very slightly off centre.
– Jake
Aug 13 '11 at 00:43
\phantom to centre the P relative to the PSPACE. You can remove it and add [xshift=2cm] to the P node.
– Alan Munn
Aug 13 '11 at 01:37
qtree. (It is, after allqtreeand notqgraph:-)) But it should be fairly easy to do intikz-qtreeI think. Since the basic syntax is the same, buttikz-qtreeis much more powerful, I would start there. – Alan Munn Aug 12 '11 at 22:50tikz-qtreecode? – Sadeq Dousti Aug 12 '11 at 22:55