Persistent Depressive Disorder: Treatment Threshold
Nothing about her symptoms has ever looked severe enough to seem urgent at a single visit — six years of that same low-grade weight is exactly what makes the case for treating it now.
V.C., a 36-year-old paralegal, has described feeling 'low-grade tired and flat' for as long as she can clearly remember, which on careful history taking dates back at least six years — persistent poor energy, mild anhedonia, difficulty concentrating, and a pervasive sense that nothing feels particularly satisfying, without ever escalating into an acute crisis or a period severe enough that she or anyone around her identified it as a discrete depressive episode. She still holds her job, maintains her friendships, and describes this state as simply 'how I am' rather than as an illness — she came in today for an unrelated concern and mentioned it almost as an aside when her physician asked how she'd been doing generally.
Her PHQ-9 today is 12 — moderate range, but she has scored similarly at her past three annual physicals, each time without prompting any specific follow-up, since no single visit's number looked acute enough to flag on its own. She has no history of a distinct major depressive episode superimposed on this baseline, no other chronic illness, and no prior psychiatric treatment of any kind.
This pattern meets criteria for persistent depressive disorder — a chronic, lower-intensity depressive syndrome lasting two years or more — which raises a real question about treatment threshold that acute major depression doesn't pose in the same way. Nothing about her presentation looks like an emergency, and PDD's own chronic, low-grade shape has historically led clinicians to under-treat it relative to acute major depression, on the reasoning that if it hasn't required treatment for six years, it may not need it now. Against that reasoning sits the cumulative real-world impairment of six years spent this way, and randomized evidence — most notably a large chronic-depression trial from the early 2000s — showing that combined medication and psychotherapy outperformed either alone in exactly this kind of persistent presentation.
At the annual physical follow-up
I don't want the fact that this has never looked acute to be mistaken for evidence it doesn't need treatment — six years of a PHQ-9 sitting at 10 to 13 is real, sustained impairment that simply never crossed a threshold dramatic enough for anyone to flag it, which is exactly the pattern that leads to persistent depressive disorder being systematically under-treated relative to major depression.
The evidence supports treating this actively rather than waiting for it to become more severe — a landmark chronic-depression trial found that combined medication and psychotherapy produced meaningfully better outcomes than either alone in a presentation shaped very much like hers, which argues against defaulting to psychotherapy alone or medication alone as if this were a milder problem needing a lighter response.
Her six-year duration without any acute escalation isn't a sign this is mild — it's the defining feature of persistent depressive disorder itself, and the randomized evidence in this specific population supports a combined approach rather than a stepped, wait-and-see one.
I'd frame the conversation with her around exactly that point — this isn't a personality trait or a permanent baseline, it's a treatable, sustained clinical pattern, and naming it clearly seems to matter given she walked in today describing it as an aside rather than a concern. Starting an SSRI alongside a referral to therapy targeting chronic depression specifically gives her the combined approach the evidence actually supports, rather than picking one arm of it by default.
Sertraline 50mg was started alongside a referral to psychotherapy specifically suited to chronic depressive presentations, with V.C.'s six-year symptom pattern explicitly named and explained as persistent depressive disorder rather than left as an undiagnosed personal baseline.
V.C.'s own reaction — visible relief at hearing a name and a plan for something she'd assumed was just her personality — became part of the documented rationale for treating proactively rather than continuing to wait for a more acute threshold that, by definition, this particular disorder may never reach.