Section of the online decision aid	Description
1. Mood questionnaire (PHQ‐9; completed in the waiting room before the decision appointment)	All participants completed the PHQ‐9, the results of which were shared with the clinician.
2. “What Matters to You?” (completed in the waiting room before the decision appointment)	All participants completed this section, which was designed to elicit personal needs, preferences and values around different treatment options for depression. The results of this were shared with the clinician in the decision appointment and were revisited after section Design (“Treatment Options”) was viewed and discussed.
3. “Treatment Options” (Viewed in the decision appointment to facilitate conversation about evidence and client preferences between the client and clinician)	Depending on mood severity (based on results of PHQ‐9 and clinician assessment), participants viewed one of three sections of the decision aid (3a, 3b or 3c).
a. Mild depression: “Should I make lifestyle changes or use guided self‐help?”	Provided details of lifestyle changes (eg fact sheets on healthy eating, exercise, sleep hygiene) and comparison of guided self‐help options (e‐mental health programs such as MoodGYMa, E‐Coucha and ReachOut Centralb).
b. Mild‐moderate depression: “Should I undertake cognitive behavioural therapy or not?”	Provided details of CBT (including fact sheet) and comparison of CBT vs no treatment, including a graphc , d depicting chance of “getting better” (remission) within 12 weeks.
c. Moderate‐severe depression: “Should I take antidepressant medication in addition to cognitive behavioural therapy?”	Provided details of CBT and SSRI medication (including fact sheets) and comparison between CBT vs CBT plus fluoxetine, including a graphc , d depicting chance of “getting better” (remission) within 12 weeks and a graph depicting chance of experiencing suicidal thoughts and behaviours within 12 weeks.
4. “Your Decision” (completed with the clinician in the decision appointment)	All participants completed this after viewing Section Design. Based on the Ottawa Personal Decision Guidee, known causes of decisional conflict were listed for discussion. Participants were asked whether they had enough knowledge; were clear about their values; felt they had enough support and advice and were clear about their choice. A date was entered for when the decision would be revisited. If the participant was not ready to decide, then a date for their next appointment was entered.
5. “Information”	All participants had access to a section of the decision aid that provided information about depression and treatment, including fact sheets, websites, videos and audio recordings. These could be viewed before, during or after their appointment.

^aBennett K, Reynolds J, Christensen H, Griffiths KM. e‐hub: an online self‐help mental health service in the community. Med J Aust. 2010;192(11 Suppl):S48‐52.

^bBurns JM, Webb M, Durkin LA, Hickie IB. Reach Out Central: a serious game designed to engage young men to improve mental health and wellbeing. Med J Aust. 2010;192(11 Suppl):S27‐30.

^cNB: All graphs were developed in line with the International Patient Decision Aids Standards.

^dTrevena LJ, Zikmund‐Fisher BJ, Edwards A, Gaissmaier W, Galesic M, Han PKL, et al. Presenting quantitative information about decision outcomes: a risk communication primer for patient decision aid developers. BMC Med Inform Decis Mak. 2013;13(Suppl 2):S7.

^eO'Connor A, Stacey D, Jacobsen MJ. Ottawa Personal Decision Guide Ottawa, Canada: Ottawa Hospital Research Institute and University of Ottawa; 2016 [cited 2016 11th July 2016]. Available from: https://decisionaid.ohri.ca/decguide.html.