Table 3 Comparison of two potential short forms selected through a combination of psychometric properties and content validity considerations

1. Depressed mood most of day

I felt unhappy

x

x

I felt depressed

x

2. Little interest or pleasure in doing things

I had trouble enjoying the things I used to enjoy

x

I felt I had nothing to look forward to

x

3. Symptoms: psychomotor retardation or agitation

I reacted slowly to things that were done or said

x

5. Symptoms: fatigue

I felt that everything I did was an effort

x

6. Symptoms: worthlessness

I felt I was not as good as other people

x

I felt worthless

x

I felt like a failure

x

7. Symptoms: excessive guilt

I felt guilty

x

8. Symptoms: diminished ability to think/ concentrate or indecisiveness

I had trouble making decisions

x

9. Symptoms: suicidal ideation

I felt I had no reason for living

x

I felt like I wanted to give up on everything

x

10. Symptoms: significant weight gain or loss/appetite loss

• I had little desire to eat

• I ate more than usual

• I lost weight without trying

11. Significant distress or impairment

I felt that nothing could cheer me up

x

I felt emotionally exhausted

x

 Symptoms: hopeless

I felt hopeless

x

x

 Symptoms: helpless

I felt helpless

x

 Symptoms: withdrew from others

I withdrew from others

x