In Treatment consistently portrays LGBTQ+ characters with dignity, complexity, and empathy across its seasons. Through therapy sessions, characters explore their identities and relationships, with struggles framed as personal or societal challenges. The show's approach is validating and respectful, affirming the worth of LGBTQ+ lives and experiences without resorting to harmful stereotypes.

In Treatment features April, a transgender woman, as a central patient in Season 3. Her identity is explored with depth and sensitivity within the therapeutic setting, focusing on her personal journey and self-acceptance. The portrayal is affirming, treating her identity as valid and complex, and avoiding harmful stereotypes.

The character Alex, originally Yadin in the Israeli source series "BeTipul," was established as Israeli/Jewish (white). In "In Treatment" (2008), Alex is portrayed by a Black actor, constituting a race swap.

The series explores the complexities of Jewish identity through several characters, including Dr. Paul Weston and his patients. It delves into their cultural heritage, family dynamics, and personal struggles, treating these aspects with nuance and respect without condemning the faith itself.