Table 1 The operational definitions for the Postpartum Depression Literacy Scale (PoDLiS) attributes and rationale for item generation

the ability to recognize mental health disorders

The ability to recognize postpartum depression

Items were adapted based on:

- The Depression Literacy Questionnaire (D-Lit) [12] (e.g., sleeping too much or too little may be a sign of depression, eating too much or losing interest in food may be a sign of depression, depression affects person’s memory and concentration and people with depression often hear voices that are not there),

- The Mental Health Literacy questionnaire (MHLq) in young people [14] (e.g., one of the symptoms of depression is the loss of interest or pleasure in most things),

- The Vignette Interview developed by Jorm in 2010 [11] and

- An item based on Diagnostic and Statistical Manual of Mental Disorders V TR criteria in 2013 [15] (e.g., symptoms and signs of postpartum depression last for a period of at least 2 weeks).

Knowledge and beliefs about risk factors and causes

Knowledge of risk factors and causes

Items were adapted or generated based on:

-The MacArthur Mental Health Module [16] (e.g., in your opinion, how likely is it that NAME’s situation might be caused by a genetic or inherited problem?, in your opinion, how likely is it that NAME’s situation might be caused by stressful circumstances in his/her life? and in your opinion, how likely is it that NAME’s situation might be caused by bad character?),

- The work of Thorsteinsson et al. in 2014 [11] (e.g., hormonal changes, lack of social support, financial problems and obstetric factors),

- The qualitative study of Ugarriza in 2002 [17] (e.g., difficult or unsuccessful breastfeeding and inability to have a vaginal delivery) and -The study of Robertson et al. in 2004 [18] (e.g., a previous history of depression).

knowledge and beliefs regarding self-help strategies

Knowledge and beliefs of self-care activities

Items included knowledge and beliefs of common strategies typically recommended such as physical activity, good sleep and having a balanced diet. Items were adapted or generated based on:

- The qualitative study of Guy et al. in 2014 [19] (e.g., getting out of the house, seeking employment, allowing emotions out through activities like crying and going to church),

-The work of Thorsteinsson et al. in 2014 [11] (e.g., childcare),

- The qualitative study of Abrams et al. in 2009 [20] (e.g., religious practices, prayer and physical exercise),

-The work of Letourneau et al. in 2007 [21] and Ugarriza in 2002 [17] (e.g., infant care and household chores from intimate partners, trusted family members, and friends), and

- The Mental Health Literacy questionnaire (MHLq) in young people [14] (e.g., good sleep helps to improve mental health, having a balanced diet helps to improve mental health).

Knowledge and beliefs about professional help available

Items included knowledge and beliefs of mental health professionals and the services they provide. Items were included or adapted based on:

- The Depression Literacy Questionnaire (D-Lit) [12] (e.g., clinical psychologists can prescribe antidepressants, most people with depression need to be hospitalized, people with depression should stop taking antidepressants as soon as they feel better and antidepressants are addictive).

- The scale of attitudes toward seeking psychological help [22] (e.g., although there are clinics for people with mental troubles, I would not have much faith in them and a person with an emotional problem is not likely to solve it alone, he is likely to solve it with professional help),

- The Mental Health Knowledge Schedule (MAKS) [23] [e.g., psychotherapy (for example, talking therapy or counselling) can be an effective treatment for people with mental health problems],

- The study of Angermeyer et al. in 1993 [24] (e.g., If taken for long, these drugs cause irreversible brain damage), and

-The mental health literacy scale (MHLS) [25] (e.g., I believe treatment for a mental illness, provided by a mental health professional, would not be effective).

Attitudes which promote recognition and appropriate help-seeking

Attitudes which facilitate recognition of postpartum depression and appropriate help-seeking

Items included attitudes that impact on recognition of postpartum depression and willingness to engage in help-seeking behavior. Items were adapted or included based on:

- The mental health literacy scale (MHLS) [25] (e.g., people with a mental illness could snap out of it if they wanted, a mental illness is a sign of personal weakness, It is best to avoid people with a mental illness so that you don’t develop this problem, If I had a mental illness I would not tell anyone, If I had a mental illness, I would not seek help from a mental health professional and seeing a mental health professional means you are not strong enough to manage your own difficulties),

- The Barriers Scale [7] (e.g., be afraid of what my family and/or friends might think of me for attending psychology and/or psychiatry appointments),

- The study of Mcluckie et al. in 2014 [26] (e.g., Most people who have a mental illness are dangerous and violent),

- The scale of attitudes toward seeking psychological help [22] (e.g., I would rather live with certain mental conflicts than go through the ordeal of getting psychiatric treatment and emotional difficulties, like many things, tend to work out by themselves) and

- The study of Abrams et al. in 2009 [20] (e.g., good mothers don’t get depressed, People tell me this is normal and PPD means you’re crazy).

Knowledge of how to seek mental health information

Knowledge of how to seek information related to postpartum depression

Items were adapted based on:

- The mental health literacy scale (MHLS) [25] [e.g., I am confident that I know where to seek information about mental illness, I am confident using the computer or telephone to seek information about mental illness and I am confident I have access to resources (e.g., GP, internet, friends) that I can use to seek information about mental illness],

- The health literacy measure for adolescents (HELMA) [27] (e.g., I am able to ask others about health information that I need).

- Items were also included appraisal of information and generated by authors (e.g., I can appraise the accuracy of information about postpartum depression on the radio and television, I can appraise the accuracy of information about postpartum depression on the Internet and I can appraise the accuracy of advices about postpartum depression which given me by friends and family members).