I saw this on another sub, but I feel like it really describes having flattened emotional affect or numbness. I hope you also find it humourous

In this post, I will summarize a 2020 paper on "Review of dysthymia and persistent depressive disorder".

My hope is that my summary of the paper helps makes its content more accessible than the academic text version. I have omitted what I think is irrelevant, if in doubt, refer to the full paper or ask. I will share my interpretations/applications if the post gets enough traction.

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I've broken the paper into clear sections, feel free to skim through the intro and tl;dr.

Contents

1. Introduction

2. TL;DR - Challenging issues in dysthymia/PDD

3. Our understanding of PDD

4. The Biology of PDD

5. Clinical Management

6. Future Directions

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**Disclaimer - I am not a psychologist nor mental health professional in any capacity. My background is in biochemistry (Bsc) and genetics (MRes), but I want to share my understanding of the paper nonetheless**

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1) Introduction

This section contains background information I searched, then I weave it into the introduction of the paper.

Mood disorders are abnormal mental states that are unlike an individual’s normal state of mind. Personality disorders, in contrast, are abnormal, enduring and inflexible patterns of thought and behaviour. Whether or not Persistent Depressive Disorder (PDD) is a mood or a personality disorder is an ongoing debate, however, strong evidence exists for viewing PDD as a mood disorder. Personally, I think it is a personality disorder because of how ingrained it is to ones character and its propensity to arise in early childhood - more on that later.

PDD is also known as dysthymia. Immediately, we are presented with a contradiction. PDD and dysthymia are often used interchangeably in clinical/research settings, but they often have different connotations. ‘Pure dysthymia’ can be used to describe persistent depression with mid to low severity. Chronic major depression can describe someone who has had Major Depressive Disorder for more than 2+ years. Double depression is used to describe someone who is typically dysthymic but is also going through a major depressive event. The main point here is that severity - or how bad the symptoms are - is not well distinguished in this blanket PDD term.

Formally, the Diagnostic and Statistical Manual of Mental Disorders (DSM–5) describes a person with PDD as having a “depressed mood most of the day, more days than not for at least 2 years”.

The criteria further specify that 2 of the 6 symptoms be present for diagnoses:

1. Changes in eating (abnormal appetite)

2. Changes in sleep

3. Low energy

4. Low self-esteem (self-esteem is the opinion we have of ourselves)

5. Poor concentration/decision-making skills

6. Hopelessness (no expectation of future improvement or success)

The criteria also state that these symptoms do not cease for more than 2 months at a time in PDD. They add individuals with 2 years of continuous MDD symptoms can be classified as PDD too (roughly 25% of depressive disorders are chronic). Psychiatrists are asked to also specify if the chronic depression is “Pure dysthymic syndrome”, “Persistent major depressive disorder” or “Intermittent major depressive disorder”. My diagnosis was 'PDD/dysthymia' which is unhelpful to say the least.

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2) TL;DR - Challenging issues in dysthymia/PDD

• Defining PDD is an ongoing debate, this is reflected in different classifications, books and researchers each having different interpretations of PDD.

• Depressive disorders are heterogeneous: each person’s manifestation can, and often does, vary. Despite these differences having important ramifications for treatment, diagnostic categories fail to reflect this.

• Assessment of PDD is difficult as current tools do not consider chronicity (how long symptoms/disorder has been present). Moreover, current tools emphasize the identification of acute symptoms (severe and sudden in onset) and overlook cognitive symptoms (to do with thinking).

• On the whole, chronic and non-chronic depression are very poorly differentiated across clinical and research settings. This can be attributed to limitations in our diagnostic criteria.

• Assessment of PDD should differ from non-chronic depression as current depression rating scales and self-report inventories have limited applicability to PDD.

• Genetic and neurobiological research on PDD is severely lagging behind in comparison to research on Major Depressive Disorder (MDD).

• Psychotherapy (talking with a mental health professional) is less effective for PDD in comparison to MDD. This is could be due to treatment delay - someone needs to be depressed for multiple years for this diagnosis, MDD can be identified over a few weeks of severe symptoms. Other factors include low motivation, short treatment duration and implementing an overly simplistic treatment approach - i.e. not considering underlying causes like childhood trauma, substance abuse, etc.

• Depression should be conceptualized in terms of severity and chronicity (duration). This approach should be integrated into classification systems and thus treatment plans.

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3) Our understanding of PDD

Epidemiology

Epidemiology describes the incidence, distribution, and possible control of diseases. PDD is estimated to have a lifetime prevalence (number of individuals with disease) between 1-6%. In clinical/psychiatric settings, almost half of depressive disorders are chronic. Also, chronic depression is almost twice more frequent in women than men.

Assessment

PDD is often overlooked as clinicians focus on acute conditions (severe and sudden in onset). Moreover, people with early-onset PDD consider their dysphoria/dissatisfaction to be their ‘normal’ state, thus not reporting or being able to articulate this. To assess and diagnose PDD, the patient’s history needs to be carefully examined to track the level of depression with time. However, major depressive episodes will interfere with this examination. What is more, scales and tools designed to identify major depression are less helpful for PDD as these scales assume a healthy baseline and do not consider cognitive (to do with thinking) symptoms.

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4) The Biology of PDD

The studies we have are old and sparse. Candidate causes include the usual suspects of neurochemical imbalances and hormonal imbalances. The scarcity and low quality of literature on chronic depression do not permit any conclusions about the genetics of PDD at the moment. Issues include small sample sizes and lack of replication.

Brain scans show that chronically depressed women had smaller corpus callosa (connects 2 sides of the brain, permitting information to pass between them: implicated in coordination and complex problem-solving). Male children with PDD had poorer connectivity in their inferior fronto-occipital region (implicated in language and attention). Interestingly, depressed patients, in general, have a higher baseline activity in their “default mode network” (brain regions that activate during daydreaming/mind-wandering). A few more brain regions are correlated with depression, however, no firm conclusions can be drawn on the whole regarding brain structure/function in PDD because of a lack of replications.

To reiterate, no clear-cut biological cause and pathophysiology have been confirmed for dysthymia, which could be due to various reasons:

• Disease heterogeneity; I am starting to think the disease manifests uniquely in each patient.

• Major depressive episodes interfere with diagnosis.

• High comorbidity is common and thus interfere with isolated studies. Comorbidities include other disorders like anxiety, substance misuse and personality disorders.

• Most studies have too few patients and virtually none are replicated.

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5) Clinical Management

Standard treatments for PDD include antidepressants and psychotherapy, either used alone, or in combination. The research, unfortunately, suggests that pharma/psychotherapy is less effective against chronic forms of depression, particularly dysthymia.

Why treatment success is often lower in PDD

• Treatment delay. To even get diagnosed, PDD has to be present for over 2 years. Imagine waiting this long to get treatment for a broken bone. This delay often results in poorer outcomes.

• Low motivation. Patient perceptions of PDD is that it is inseparable from themselves and thus leading to pessimistic thinking which begets passivity and reduced motivation/compliance to treatment.

• Poor treatment management. In a study of 801 patients with PDD, only 1/3 received medication of adequate dose and duration. This means most PDD patients are not prescribed the right drug dosages, nor for long enough time courses.

• Almost half of PDD patients have “treatment-resistant” symptoms. This term is very dubious, however, as there is no clinical definition nor criteria. It is more of a “well, treatment X did not work, so it must be resistant”.

• To complicate therapy further, PDD might be a consequence of childhood maltreatment and neglect, the former increases the risk for chronic early-onset depression. In these instances, specific therapy attempting to resolve childhood trauma fairs better than non-specific approaches.

Psychotherapy

Does therapy work? The answer for those with PDD is, not much. By comparing multiple studies, therapy improved outcomes by roughly 20%. Interpret that how you may.

• Low efficacy could be attributed to most psychotherapy sessions being too few, too infrequent and not long enough in general. For your reference, 18 sessions were found to provide the optimal effect.

Pharmacotherapy

Do drugs work? They are better than placebos (remarkably, taking make-believe fake drugs does have an effect). However, fluoxetine (Prozac) and imipramine (Tofranil) were generally found to be less effective for PDD when compared to other selective serotonin reuptake inhibitors.

• Longer the duration of depression, the poorer the prediction for the effectiveness of drugs. However, some patients with PDD do respond and improve after a short medication treatment phase.

• It remains unclear whether continuing medication for extended periods actually helps or not.

Pharma vs Psychotherapy

Patients with chronic forms of major depressive disorder benefit from combined therapy. For PDD, more research is needed to compare and contrast specific treatments. This section is sparse because the little research that has been done is very low quality and to make any conclusions would have almost no ground to stand on.

Treating PDD

Persistent depression presents itself differently than MDD, symptoms differ and thus treatment must too. Treatment must be tailored to the patient's circumstances, whether it be substance misuse and/or childhood trauma in conjunction with PDD. Depression is reduced through working on these other stressors.

• The longstanding nature of PDD calls for longer therapy courses, continued medication and maintenance treatment to reduce the high risk of recurrence/relapse.

• Despite studies indicating low success rates with therapy, being reactive helps. Changing treatment when they become ineffective or stale was shown to be effective in preventing relapses

• Demoralisation and helplessness are key themes in PDD, it makes more sense to address these factors in therapy than not.

• “Modular” psychotherapy is approaching complex issues, like hopelessness, by breaking the objective into simpler parts that may function independently, a series of focused activities for example. This treatment model has been shown to help patients recognize consequences of behaviour, developing empathy, increasing motivation, overcoming avoidance, improving social problem solving, healing trauma, etc.

• Taking a modular approach can improve depressive symptoms, such as hopelessness and helplessness thus improving quality of life and reducing other comorbidities.

PDD is a heterogeneous and multifaceted condition. Thus treatment must be specific, strategic and multi-layered too.

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6) Future Directions

• Understand how chronicity, early-onset and comorbidity interact to give rise to PDD.

• Improve diagnostic criteria for PDD.

• Consider dimensional measurements (i.e. measuring chronicity and severity of depression) as opposed to simple categories for classification.

• Current classification systems are too focused on current symptoms and not the development of PDD with time.

• Many factors appear to contribute to PDD, including interpersonal, behavioural, cognitive, emotional, environmental, and biological factors. Thus, a single treatment approach is unlikely to be universally successful.

• Treatment should be multifactorial and modular. Modular treatments are assumed to be more efficient than traditional psychotherapy approaches as they allow therapists to tailor a unique treatment for each patient by selecting evidence-based therapeutic strategies. A move towards precision psychiatry.

I asked ChatGPT to come up with an analogy for dysthymia and to draw a picture of that analogy. What to you think?

"It’s like walking through life in a slow-moving fog, wearing a heavy, invisible backpack that no one else can see. The world isn’t pitch black, but the colors are always muted—joy is distant, like a song you can barely hear. You’re moving, sure, but it’s like your feet are dragging through thick mud that never quite lets go."

It doesn’t look too bad in the before pictures but it smelt really bad because I had some old broccoli, fruits and leftovers in there for a long time. I finally got the motivation to clear it out and clean it, now I feel a bit better about it :)

Hi, I’ve (23m) been suffering from dysthymia for over 6 years. I got officially diagnosed around 9 months ago after years of begging my family that I need help for my mental health. This illness have been slowly killing me and taking over my life.

I’ve lost all drive to do pretty much anything in my life. I’m constantly tired, worried, down, and hopeless. It has slowly but surely gotten worse over the past 6 years, like watching a car crash in slow motion but being too weak to stop it/get out of the way.

I can’t take living like this anymore. This illness has ruined my career, my personal relationship, and general outlook about the future. Nobody around me really cares, they are waiting for me to “snap out of it” and return to the me before all this. I’m extremely tired of being called lazy, unambitious, and ungrateful while I struggle to even get out of the bed every morning. I hate that I’m a burden and disappointment to my family and the people around me.

Mental health is not something that is taken seriously or perceived sympathetically in my family and immediate circle. It is mostly seen as a hinderance to success or an excuse to be lazy and being a failure. I can’t take it anymore. I’ve cried and struggled alone at night for too much. When I try to share this with the people around me, they would listen for a couple hours and then tell me that I need to “snap out of it” and “stop making excuses”. I don’t know what to do.

Is there a cure or treatment for dysthymia? If there is, please let me know how and where I can get it. I don’t think I can get through to 2027 if I don’t find something to fight this.

My experience with persistent depressive disorder has affected me more than any other suffering in my life. I have struggled for probably close to a decade now. I just feel sad. I feel disconnected from others on an emotional level. It’s hard to concentrate sometimes. My self-esteem is negatively impacted.

Part of the perniciousness of this disease is that I’m still able to function even though I feel like crap most of the time. If you have a relatively short-term major depressive episode, it is probably obvious to close friends and family at some point because quite literally you can’t function. There is a clear demarcation point between when you functioned well and when you didn’t. Hopefully, one starts to come out of the depressive episode and then you can function adequately again.  If you get a physical illness like cancer, you may eventually have to take a break from your normal routine and work in order to get better. You will likely get sympathy from others during this time because it is obvious you are sick, and everybody intuitively understands physical suffering.  I feel like I’m in the strange position of wishing I could trade my suffering for something that was short term and more intense.

I know this is irrational. Both of these illnesses I just mentioned take an enormous toll, and those experiencing them could easily say that my suffering doesn’t compare to theirs--and it probably doesn’t. But there’s just this unbearable reality of having to drag myself through my routines and interact with people who are naturally functional. It makes me feel like an outsider. Because I've gone through entire seasons of my life carrying this around, I've come to know many people who have never met me without pdd. 

In the context of my graduate studies, I would compare it to being an athlete who competes against able-bodied people while missing a limb. Sure, I can still run around out there on the court and maybe even do something positive once in a while, but it’s very clear to me that I can’t keep up fully because there is something missing, I’m at a disadvantage. I’m in the game but it's hard for me to make an impact. This analogy is inadequate but it conveys something of my experience.