“A Summer in the Cage” is filmmaker Ben Selkow’s feature-length documentary chronicling his friend Sam’s battle with manic-depressive illness, also known as bipolar disorder. The film follows Sam for seven years as he suffers delusional manic episodes, battles paralyzing depressions, and tries to escape the legacy of his bipolar father who committed suicide when Sam was eight years old. By showing the difficult emotional impact of being bipolar on Sam, his family, all those who care about him and the filmmaker, “A Summer in the Cage” hopes to put a human face on an illness that affects millions of American families. But as this dramatic story unfolds and heads to an explosive standoff, it also becomes a unique tale about friendship and the ethical responsibilities of a documentary filmmaker.