By the time your appointment arrives, you feel better. Describing Tuesday starts to sound, even to you, like an exaggeration.
The argument took hours to recover from. After the immediate distress passed, the exhaustion and lack of interest that had been there for weeks remained. Now a better morning makes you wonder how much of that still belongs in the conversation.
Borderline personality disorder, or BPD, and depression can occur together. An assessment needs both the changes in how you feel and the symptoms that persist across time. Feeling better after reassurance, or during one appointment, does not by itself rule out depression or establish what else is happening.[1,2]
What does Affective Instability mean?
Affective instability means marked changes in emotion, including how quickly a feeling rises, how intense it becomes, and how long it takes to settle. That describes a pattern of change; the assessment also needs to ask about low mood or loss of interest that continues between upsetting events.[1,2]
BPD can involve difficulty regulating emotions, an unstable sense of self, relationship difficulties, emptiness, and other symptoms. Experiences vary considerably. Affective instability is one part of a possible pattern, not a diagnosis you can make from a difficult afternoon.[1]
A delayed reply or an argument can be upsetting for many reasons. Recognizing yourself in an example does not establish BPD. The broader history and effects on your life matter.
A 2024 study asked people experiencing depressive episodes to report how they felt repeatedly during daily life. In that sample, negative emotions were less stable in participants with co-occurring BPD than in those with major depression alone.[5] These are group-level findings, not a way to diagnose a person from a change in mood.
What can remain after the immediate Distress passes?
Suppose an argument is resolved and you no longer fear that the relationship is ending. That relief matters. Yet you are still waking early, struggling to eat, unable to concentrate, and finding little pleasure in things that usually interest you. The reassurance answered one concern while other difficulties remained.[1,2]
Depression is assessed through symptoms, duration, and effects on daily life. Major depression generally involves low mood or loss of interest, along with other symptoms, most of the day, nearly every day, for at least two weeks. A clinician considers the full picture, including other possible explanations. You do not need to wait two weeks to seek help when you are struggling.[2]
“I felt much better when we made up” and “I have barely enjoyed anything for weeks” can both belong in what you tell your clinician. Relief from one source of distress does not settle the broader assessment.[1,2]
You do not have to feel it again to describe it accurately
At the appointment, you can smile and follow the conversation. “I could barely function” sounds at odds with how you feel now, so the account gets smaller: “It was a rough few days. I’m fine now.” The canceled plans, missed meals, or hours spent unable to begin anything may go unmentioned. This reporting difficulty can occur in many circumstances; it is not a defining feature of BPD.
Describe the sequence: what happened, how long the distress lasted, what became difficult to do, and what remained after the situation changed. A few concrete details are enough to begin: “We resolved the argument that night. I still missed work the next morning, and for the rest of the week I could not enjoy anything.” You do not need to recreate the feeling or prepare an exhaustive mood log.
The better morning belongs in that account too. Improvement in how you feel now and difficulty functioning earlier can both be real. Neither has to erase the other.
If a delayed reply brings an urgent need to respond, that sequence can also be useful to describe: what you feared would happen, what you felt urged to do, and what you chose. No particular response or pause is required to make the experience worth discussing.
Understanding your response does not require dismissing what happened
A person can have difficulty regulating emotions and also be responding to a real disappointment, loss, or mistreatment.
A broken agreement still deserves attention even if, on reflection, you want to respond differently. You and the clinician can examine what happened, what you understood at the time, and what response would better serve your safety and goals.
“I was hurt” and “I want a different way to respond when I am hurt” can be discussed together. Acceptance and change are both central to DBT, one treatment used for BPD.[3] Learning to pause should not become a requirement to accept whatever someone else does.
Why a calmer week may still need a closer look
Imagine having fewer conflicts because you have stopped seeing anyone, including people you miss. Compare that with a week when you stay connected, handle a disagreement, and recover enough to continue your plans. Both weeks may contain fewer arguments. Time alone can be restorative; the question is whether you are choosing it or finding it harder to participate in the life you want.
Ask what made the week calmer. Did you recover more readily while staying involved in life, or did you give up the situations that mattered to you? NICE’s BPD guidance recommends monitoring a broad range of outcomes, including functioning, self-harm, depression, and BPD symptoms.[4]
Fewer outward signs of distress should not make the remaining suffering harder to mention.
How can treatment address BPD and depression together?
A plan should address both the persistent depressive symptoms and the difficulties associated with BPD. NICE recommends treating co-occurring depression within a well-structured BPD treatment program.[4] Ask how the plan will address each concern and who will review it. Depression should not disappear from the plan simply because emotional crises are more noticeable.
DBT teaches skills for mindfulness, distress tolerance, emotion regulation, and relationships. Comprehensive DBT includes individual therapy, skills training, between-session coaching, and a consultation team for therapists. A therapist using some DBT methods in individual sessions may not offer that whole program.[3]
Ask which components are available, what the plan is for difficulties between appointments, and how safety concerns will be handled. Some needs require more support than a scheduled individual session alone can provide. A diagnosis by itself does not tell you what level of care you need.
Psychotherapy is a primary treatment for BPD. Medication is not its first-line treatment, but a prescriber may recommend medication for a co-occurring condition such as depression. Care may therefore involve more than one provider.[1]
In a longitudinal study of people with BPD, improvements in BPD often preceded improvements in co-occurring major depression, while improvements in depression did not consistently precede improvement in BPD.[6] This group-level observation does not establish which condition an individual should treat first. It reinforces why both conditions need to remain visible in the care plan.
What would meaningful progress look like for you?
You might recover from an upsetting conversation sooner and still have little energy or interest. Or your energy may improve while disagreements continue to take over the day. Review those changes separately, along with sleep, relationships, safety, and ordinary responsibilities. Progress in one area gives you something to build on while making the remaining difficulty worth discussing.[1,2,4]
At the next appointment, a useful sentence may be: “This part is better. This part still needs help.”
One good hour belongs in that conversation. So does the rest of the week.
Urgent support
If you are struggling or having thoughts of suicide, call or text 988 in the United States. In a life-threatening emergency, call 911.[1,2] MMHC does not provide emergency services; its emergency resources page lists additional support.
Getting support in New York
Manhattan Mental Health Counseling provides secure, live video psychotherapy for clients physically located in New York State. Learn about DBT therapy and ask what treatment and support are appropriate for both the mood changes and any persistent depression you are experiencing. MMHC offers DBT-informed individual therapy rather than a comprehensive DBT program. MMHC provides psychotherapy and does not prescribe or manage medication; medication questions belong with a prescriber.
Begin with a free 15-minute screening call. MMHC’s Therapy Coordinator helps with matching, and rematching is available. MMHC accepts major insurance plans and reviews benefits before care begins to explain estimated out-of-pocket costs. Start Therapy Now or call 212-960-8626.
This article is for informational purposes and is not medical advice.
References
- National Institute of Mental Health. Borderline Personality Disorder. Read source
- National Institute of Mental Health. Depression. Read source
- University of Washington, Behavioral Research & Therapy Clinics. Dialectical Behavior Therapy. Read source
- NICE. Borderline personality disorder: recognition and management (CG78), recommendations 1.3.4.7 and 1.3.6.2. Read source
- Socada JL, Söderholm JJ, Rosenström T, et al. (2024). Affect dimensions and variability during major depressive episodes: Ecological momentary assessment of unipolar, bipolar, and borderline patients and healthy controls. Journal of Psychiatric Research, 170, 408-416. DOI: 10.1016/j.jpsychires.2024.01.010. Read source
- Gunderson JG, Morey LC, Stout RL, et al. (2004). Major depressive disorder and borderline personality disorder revisited: longitudinal interactions. Journal of Clinical Psychiatry, 65(8), 1049-1056. DOI: 10.4088/JCP.v65n0804. Read source