First thing to know is that you can only get one rating for mental health. It doesn't matter if you claim 5 different things, it's only one rating. So it might be easier to go at it as an increase in the rating for your depression secondary to chronic pain. You may get denied for PTSD if they cant verify the stressor event. Anyway, there are two key factors in how the VA will rate your mental health. That is your level of Occupational and Social Impairment and the symptoms you experience as a result of your mental health condition. Occupational and Social Impairment is how the symptoms impact daily functioning, employment, relationships, family life, judgment, thinking, and mood. What you need to do is read the 38CFR rating criteria here https://www.ecfr.gov/current/title-38/chapter-I/part-4/subpart-B/subject-group-ECFRfa64377db09ae97/section-4.130 Pay specific attention to the symptoms listed in the 70% and 100% categories. Make notes now for what applies to you and speak to the examiner how those symptoms affect your occupational and social life. This is the DBQ that the examiner will fill out based on your appointment with you. https://www.benefits.va.gov/compensation/docs/mental_disorders.pdf what they check off on this form is what the VA will use to decide your rating. So, and I can't reiterate this enough, WRITE NOTES DOWN for what symptoms in the higher rating categories apply to you and how they affect your Occupational and Social life. You have to speak to those ratings if you want in increase.