A Literature Review...
Introduces a topic and explains why the topic is important (background, establish facts).
Example: Depression affects over 20% of adolescents.
If you are examining a research question through a critical lens/theory/perspective, you need to define what that is.
Example: Attachment theory (Bowlby, 1969) explains how close relationship tendencies act as a risk factor for depression. Attachment is defined as a deep and enduring bond that connects one person to another person.
Introduces all the elements in a research question by citing previous published literature relevant to the question (rather than relying on personal opinion).
Example: A wealth of research has linked attachment insecurity to depressive symptomology (Bifulco et al., 2002; Roberts, Gotlib, & Kassel, 1996; Scharfe, 2007).
Cites others who argue there is little research in the area of interest and more research is needed; OR who argue there are conflicting results in the area of interest and more research is needed.
Example: Few studies have examined the relationship between attachment theory and depression in adolescents; most studies involve only children or adults.