Conceptualizing psychiatric disorders as idiosyncratic networks of mutually reinforcing behaviors and emotions has a long history in the form of psychotherapy case conceptualizations created collaboratively by therapist and patient. However, such methods are typically unsystematic and biased by therapist assumptions. An alternative is Perceived Causal Networks (PECAN), a structured online questionnaire in which patients quantify causal relations between problematic behaviors and emotions, and responses are visualized in the form of a network. In the present study, PECAN was evaluated for clinical utility at the start of therapy for five patients screening positive for depression. As expected, the five networks were found to be highly idiosyncratic, with two revealing the expected maintaining feedback loops. Both therapists and patients evaluated the method as useful in the initial phase of a therapy treatment. Although PECAN shows promise as a clinical tool, findings suggest that the method could be improved by including contextual factors maintaining depression.