Depression / Anxiety (Chronic Mobility Impairment) Secondary to Bilateral Knee Conditions (Service-Connected)

Yes. Under 38 CFR § 3.310(a), any disability proximately caused or chronically worsened by a service-connected condition is itself service-connected. Depression / Anxiety (Chronic Mobility Impairment) is a documented secondary pairing for Bilateral Knee Conditions (Service-Connected) with strong medical evidence. A nexus letter from a qualified physician linking the two conditions is the most reliable way to establish this connection.

The gold standard is a private nexus opinion stating — to at least a 50% probability ("at least as likely as not") — that the secondary condition was caused or aggravated by the primary service-connected condition. Peer-reviewed medical literature supporting the physiological mechanism strengthens the nexus. Treatment records documenting the onset or worsening of the secondary condition in temporal relation to the primary are supporting evidence.

The VA rates Depression / Anxiety (Chronic Mobility Impairment) separately under its own 38 CFR Part 4 diagnostic code, then combines it with Bilateral Knee Conditions (Service-Connected) and all other service-connected ratings using the combined ratings formula under § 4.25. The formula applies the whole-person concept: a 50% combined existing rating plus a new 30% rating yields 65% (rounded to 70%), not 80%.

38 CFR § 3.310(a) states: "Disability which is proximately due to or the result of a service-connected disease or injury shall be service connected." The aggravation variant under § 3.310(b) applies where the primary condition permanently worsens a pre-existing disability beyond its natural progression. Both standards require a showing of nexus — a medical or scientific link between the primary condition and the secondary.

The medical evidence supporting Depression / Anxiety (Chronic Mobility Impairment) as secondary to Bilateral Knee Conditions (Service-Connected) is rated strong. Bilateral knee conditions produce depression and anxiety through chronic pain, loss of functional independence, and erosion of self-identity. Veterans whose identities are tied to physical capability (infantry, special operations, athletics) experience particularly acute psychological impact from bilateral knee disability. Chronic pain activates the same neural circuits as depression (anterior cingulate cortex, insula, prefrontal cortex), producing a neurobiological substrate for mood disorders. Loss of ability to exercise eliminates a primary endorphin source and coping mechanism. Social isolation from inability to participate in physical activities with family and peers compounds the psychological burden. Studies show MDD prevalence of 30-45% in chronic musculoskeletal pain patients.

The VA will not solicit nexus evidence on your behalf for secondary claims. In practice, a written nexus opinion from a private physician or independent medical examiner is essential — the VA's Compensation & Pension (C&P) examiner is not required to produce a favorable nexus opinion, and the VA has discretion to weigh competing opinions. Submitting a private nexus letter at the time of filing is the most reliable strategy.