Major Depressive Disorder Secondary to Ptsd: VA Rating Guide 2026

What Is Secondary Service Connection?

Secondary service connection under 38 CFR 3.310 allows VA to compensate a disability that was caused or aggravated by an already service-connected condition. You do not need to show that major depressive disorder was directly caused by your military service — only that it was caused or worsened by your service-connected Ptsd. This is one of the most powerful and underused tools in the VA claims system.

The Medical Nexus: Ptsd → Major Depressive Disorder

PTSD and depression are highly comorbid. VA rates them separately if they have distinct symptom clusters, or as a combined rating if symptoms overlap.

To establish secondary service connection for major depressive disorder, your nexus letter must state, at minimum, that it is “at least as likely as not” (50% or greater probability) that your major depressive disorder was caused or aggravated by your service-connected Ptsd. The VA uses this “at least as likely as not” standard — it does not need to be certain, just probable.

How to File for Major Depressive Disorder Secondary to Ptsd

1. Get a nexus letter from your treating physician or a private independent medical opinion (IMO) provider. The letter must explicitly state the causal connection between your Ptsd and major depressive disorder.
2. File VA Form 21-526EZ (if you haven’t already) or a supplemental claim if you’ve been previously denied.
3. List major depressive disorder as a secondary condition on your claim form, citing your service-connected Ptsd as the cause.
4. Attend your C&P exam — the examiner will evaluate the nexus. If the examiner provides a negative nexus opinion, you can rebut it with your private nexus letter.
5. If denied, file a supplemental claim with new and relevant evidence (your nexus letter) or appeal to the Board of Veterans’ Appeals.

VA Rating for Major Depressive Disorder: What to Expect

If your secondary claim is granted, VA will rate your major depressive disorder under the appropriate diagnostic code, typically at 50% for moderate severity. The rating is then combined with your existing ratings using the VA combined ratings formula — it does not simply add to your current percentage. For example, if you are currently rated 70% for Ptsd and receive a 50% rating for major depressive disorder, your combined rating would be approximately 85% (not 120%).

Nexus Letter Requirements for Major Depressive Disorder Secondary to Ptsd

A strong nexus letter for this claim should include:

• The physician’s credentials and familiarity with VA claims
• A review of your medical history showing the timeline (service-connected Ptsd predates major depressive disorder diagnosis)
• A citation to medical literature supporting the causal relationship
• The “at least as likely as not” opinion stated explicitly
• A statement that the opinion is based on a review of the claims file and examination of the veteran

Common C&P Exam Questions for This Claim

At your C&P exam for major depressive disorder secondary to Ptsd, the examiner will likely ask:

• When did your major depressive disorder symptoms begin relative to your Ptsd diagnosis?
• Has your major depressive disorder worsened since your Ptsd was diagnosed?
• What treatments have you received for major depressive disorder?
• How does major depressive disorder affect your daily functioning and ability to work?

Answer these questions honestly and specifically. Describe your worst days, not your average days. The examiner is evaluating both the nexus and the severity of your major depressive disorder.