Persistent depressive disorder and adjustment disorder

• Persistent depressive disorder (PDD) is a chronic depressive condition in which a depressed mood is present most of the day, for more days than not, for at least two years in adults, or one year in children and adolescents, together with at least two of six associated symptoms and significant impairment. ^[1]
• PDD replaced the older labels dysthymia and chronic major depression. It combines them; it now also includes chronic major depressive episodes and episodes in partial remission. ^[1][3]
• Adjustment disorder is a stress-response condition: emotional or behavioural symptoms begin within three months of an identifiable stressor, are out of proportion or impairing, and do not persist for more than six months after the stressor (or its consequences) ends. ^[4]
• Neither condition has a laboratory test. Both are clinical diagnoses. The main task is to separate them from major depression, bipolar disorder (mania or hypomania excludes PDD), grief, substance or medical causes, and from each other. ^[1][4]
• Treatment is chronic-depression treatment for PDD (antidepressants plus psychotherapy, with a longer time horizon), and low-intensity, stressor-focused support for adjustment disorder, with no drug considered first-line. ^[1][2][4]

By the end of this page you should be able to:

1. State the DSM-5-TR criteria for PDD and adjustment disorder, and the specifiers for each. ^[1][4]
2. Separate PDD from major depression, cyclothymia and bipolar disorder, from prolonged grief, and from adjustment disorder. ^[1][3][4]
3. Plan screening and assessment for chronic low mood or a recent stressor, including valid tools and the limited set of tests that help. ^[2][3]
4. Match treatment to each condition, including antidepressant dose ranges and how long treatment should continue. ^[1][2][6]
5. Recognise suicide risk and the features that convert a provisional diagnosis into major depression or post-traumatic stress disorder. ^[4][5]
6. Adapt management for children, older adults, pregnancy and low-resource settings. ^[1][2][4]

In DSM-5-TR the old diagnostic labels dysthymia and chronic major depressive disorder have been folded into this single category, which is called persistent depressive disorder (the parenthetical "dysthymia" was removed in the text revision). ^[1] The words "dysthymia" or "dysthymic disorder" are still used as the ICD-11 label and as a clinical shorthand for the milder chronic form, which is why this page uses both. ^[1]

Course subtypes. DSM-5-TR allows a person to meet full criteria for a major depressive episode continuously for two years within PDD (so-called double depression, a common and disabling picture), or to have subthreshold or partially remitted symptoms throughout. Specifiers describe whether the picture is a pure dysthymic syndrome or a persistent major depressive episode, whether anxious distress or atypical features are present, whether there is partial or full remission, whether onset was early or late, and severity (mild, moderate, severe). ^[1][3]

There is no biological test. Two conclusions from clinical work matter. First, duration is the defining feature: the low mood and its consequences simply do not let up for more than a couple of months at a time over the whole period. Second, psychosocial impairment in PDD can be as great as, or greater than, in a single major depressive episode. ^[1]

Adjustment disorder is classified in DSM-5-TR among the trauma- and stressor-related disorders rather than with mood disorders, because the symptoms must be a response to a stressor. ^[4] Specifiers describe the predominant picture: with depressed mood, with anxiety, with mixed anxiety and depressed mood, with disturbance of conduct, with mixed disturbance of emotions and conduct, and unspecified. ^[4] Delayed onset (more than three months after the stressor) or prolonged duration (more than six months without a persistent stressor) is labelled "other specified trauma- and stressor-related disorder". ^[4]

Persistent depressive disorder. Because PDD is a relatively new diagnostic category, good epidemiology is scarce. ^[1] DSM-5-TR estimates a 12-month prevalence of approximately 0.5% for dysthymia and 1.5% for chronic major depressive disorder. ^[1] In a community study of 3,720 people in Zurich, the 12-month prevalence was 15.2% for PDD with persistent major depressive episodes, 3.3% for PDD with pure dysthymia, and 28.2% for major depressive disorder. ^[1] For context, the DSM-5-TR 12-month prevalence of major depressive disorder in the United States is approximately 7%, with higher prevalence in women and steeper rates in young people, and the prevalence of major depression may vary eight- to nine-fold across the world. ^[1]

CANMAT notes that roughly 20 to 30% of people with a major depressive episode have a chronic course lasting more than two years and are therefore effectively in the PDD category. ^[3] PDD begins early for many: antecedents include greater childhood adversity and maltreatment, childhood loss of a parent, higher rates of chronic depression in relatives, and earlier onset of depression. ^[1] Estimates of depression may be low in older adults because depressive symptoms are misattributed to the physical disorders that increase with age. ^[1]

Adjustment disorder. Adjustment disorder is one of the most commonly diagnosed mental health conditions and is often thought of as mild and short-lived, yet it accounts for real disability. ^[4][5] It is present in an estimated 5 to 20% of people making outpatient mental health visits, and population-based prevalence estimates, which use varying criteria, suggest a wide range from 1 to 17%. ^[4] It is common in general hospitals and in consultation-liaison settings, where a new diagnosis, operation or bereavement is recent. ^[4]

PDD. No single cause has been found, and the evidence points to interacting layers. ^[1] Risk factors include genetics, epigenetics, prior mental illness, neuroticism and high anxiety states, low self-worth, trauma, life stressors and social determinants of health. ^[1] Strong contributors are childhood maltreatment and adversity (emotional abuse, physical abuse, neglect, bullying), childhood loss of a parent, a family history of chronic depression, and earlier age of onset of depression. ^[1] Comorbidity with borderline personality disorder is high, suggesting shared temamental vulnerability, interpersonal stress and childhood maltreatment. ^[1] Interpersonal problems are prominent: people with PDD report significantly more childhood maltreatment and interpersonal difficulty, lower perceived social support and more loneliness. ^[1]

Adjustment disorder. The trigger is the diagnosis. The stressor can be single or repeated, mild or severe, and can be a common developmental event (becoming a parent), an acute loss (losing a job), an interpersonal setback or an ongoing burden (caring for a disabled family member). ^[4] The same event can be a trigger in one person and a manageable setback in another; the difference lies in the meaning of the event, the person's coping resources and the social support around them. ^[4] Death of a loved one can precipitate an adjustment disorder, but clinician judgement is needed to distinguish a culturally expected grief response or prolonged grief disorder. ^[4]

PDD. The pathophysiology is unknown: no studies of PDD itself exist, and older studies of dysthymia and chronic major depression have not been replicated. ^[1] Early work implicated serotonergic abnormalities, immune system dysregulation, neuroendocrine changes and sleep alterations. ^[1] Imaging has produced no firm conclusion, although the prefrontal cortex, anterior cingulate, amygdala and hippocampus are repeatedly implicated. ^[1] Gene studies are too small and unreplicated. ^[1] In clinical terms, PDD behaves as a disorder of chronic low-grade dysregulation rather than a single triggered episode, which is consistent with its resistance to brief treatment. ^[1] Adjustment disorder. No biomarker or neurobiological signature is established. The working model is a stress-response syndrome in which cognitive appraisal, coping capacity and social context interact with biology to produce transient, functionally impairing symptoms. ^[4] Removal or resolution of the stressor and restoration of safety and support usually allows recovery.

PDD is often missed precisely because it is chronic and partly normalised. ^[1] The person may describe feeling "down in the dumps", with low energy, impaired concentration and decision making, low self-esteem and hopelessness. ^[1] Associated features mirror the depressive symptom groups: poor or increased appetite, insomnia or hypersomnia, hopelessness. ^[1] History taking should include a careful chronology, precipitating and perpetuating factors, comorbid diagnoses and any acute episodes before or after the low-grade periods. ^[1] Past psychiatric history (manic or hypomanic episodes, hospitalisations, treatments and adherence, suicidal behaviour) is essential, as is substance and medical history, family history and developmental history, including childhood adversity. ^[1] Collateral information is very helpful. ^[1]

Risk assessment is mandatory and repeated: people with PDD have a higher risk of suicide than people without it, and childhood emotional abuse has been associated with suicidal behaviour in this group. ^[1] Sleep disturbance compounds the risk: in one study sleep problems were associated with a higher suicide risk, and people with PDD had an estimated 7.195-fold higher suicide risk than people without PDD. ^[1] Assessment of harm to self and others, and of substance use, should be part of every contact. ^[1]

On mental state examination, appearance and self-care may be neglected, psychomotor activity slowed, affect constricted, and thought content may show guilt, pessimism or, less commonly, psychotic features. ^[1] Insight varies: some patients partially recognise the problem, others do not, and judgement may be impaired. ^[1]

Adjustment disorder usually begins within days of the stressor. ^[4] The three symptom categories are depressed mood, anxiety and disturbance of conduct; most people present with a mixture rather than one in isolation. ^[4] The reaction must be clinically significant (distress out of proportion, or significant impairment of functioning) and must not meet criteria for another mental disorder. ^[4] People with adjustment disorder have an increased risk of suicide attempts and completed suicide. ^[4]

In PDD, perform a general medical and neurological examination, bearing in mind that medical illness can mimic or worsen the presentation, plus a mental state examination as above. ^[1] In adjustment disorder, examination is directed at safety, the nature and timeline of the stressor, impact on functioning, and exclusion of another psychiatric or medical disorder. ^[4]

The two questions are (a) is this really PDD or adjustment, and (b) which overlapping condition does it actually represent? The table covers the common mimics.

There is no diagnostic test for either condition. Investigations exist to exclude organic causes and substance use, and to inform safe treatment. ^[1][4]

The full DSM-5-TR criteria are paraphrased below. They should be used with clinical judgement rather than as a checklist alone. ^[1][4]

This section follows the named guidelines: DSM-5-TR for diagnosis, NICE NG222 (published 29 June 2022, last reviewed 30 January 2026) for adult depression and chronic symptoms, the APA Clinical Practice Guideline (adopted February 2019) for doses and psychotherapies, and the CANMAT 2023 update (published 2024) for the chronic-course framework. ^[1][2][3][6]

• Base treatment on shared decision making, and respect preference, past experience and goals. ^[2][3]
• Treat the depression and the physical health together; chronic illness and depression worsen each other. ^[3]
• Review how well treatment is working between two and four weeks after starting it; earlier review at one week for people aged 18 to 25 or at suicide risk. ^[2]
• After remission, continue at the effective dose for at least six months; longer (CANMAT suggests 6 to 24 months, or longer if indicated) for recurrent or chronic illness. ^[2][3]
• Reduce antidepressant dose gradually when stopping, accounting for half-life; paroxetine and venlafaxine are prone to withdrawal, and fluoxetine can sometimes be tapered by alternate-day dosing. ^[2]
• Monitor mood, function, adverse effects and suicidal ideation, and make safety plans early in treatment. ^[2]

Treatment success in PDD may be lower because of delayed diagnosis, hopelessness and inadequate duration, so it pays to start promptly and persist. ^[1] History matters: people with PDD often have childhood trauma, and those with trauma histories may do better with targeted therapies such as the Cognitive Behavioral Analysis System of Psychotherapy (CBASP). ^[1] Studies of dysthymia showing little benefit may have been flawed by too few sessions; longer treatment and more sessions improve outcomes. ^[1] Combining medication and psychotherapy produces higher response rates and better functioning, even though there is not a clear additive benefit on symptoms alone. ^[1] In children and adolescents, the American Association of Child and Adolescent Psychiatrists guideline suggests cognitive behavioural therapy or interpersonal psychotherapy, with insufficient evidence on SSRI benefit or harm in this age group. ^[1]

Psychotherapies with evidence in chronic depression include individual and group CBT, behavioural activation, interpersonal therapy and support. CBASP was developed specifically for chronic depression. Combinations are used when response is partial. ^[1][2][6]

Antidepressants do work in PDD, but response rates are lower and remission less likely than in episodic depression. ^[3] A 2014 meta-analysis found fluoxetine, paroxetine, sertraline, moclobemide, imipramine, ritanserin, amisulpride and acetyl-l-carnitine more effective than placebo in pure dysthymia and chronic forms of depression; interpersonal psychotherapy alone was less effective than IPT plus medication; and the evidence was insufficient for mirtazapine, venlafaxine and psychodynamic psychotherapy. ^[1] CANMAT recommends treating PDD within a difficult-to-treat depression framework, in which the goal shifts from symptom remission to quality of life and functioning when remission is not reached. ^[3]

For typical adult dose ranges, the APA 2019 adult treatment page lists the following. Always check the product label and local formulary, and start low and titrate with comorbidity and side effects in mind. ^[6]

NICE NG222 supports SSRIs, SNRIs and TCAs for chronic depressive symptoms, and combination of a psychological therapy with an antidepressant may be more effective, on average, than either alone; other medications (TCAs, phenelzine, amisulpride and moclobemide) may be considered as alternatives after specialist advice if symptoms do not respond to SSRIs or SNRIs. ^[2] Augmentation with lithium or an oral antipsychotic follows the standard monitoring (lithium plasma levels usually at or above 0.4 mmol per litre for augmentation, not exceeding 1.0 mmol per litre; 0.4 to 0.6 mmol per litre for adults 65 and over; renal, thyroid, calcium and weight checks; antipsychotic cardiometabolic and QT monitoring). ^[2] For treatment-resistant depression, neuromodulation (ECT, TMS, esketamine in certified settings) is considered within the general MDD pathway. ^[2]

Adjustment disorder is not really a drug-treatable condition. ^[4] The best evidence is for psychosocial care: safety, self-care, supportive relationships, maintaining a daily routine and community involvement, and modification of the stressor or environment where possible. ^[4] Treatment is difficult while the stressor is ongoing or recurs, and social instability undermines other interventions. ^[4]

Psychotherapy is the main offered intervention, although the evidence base is limited and heterogeneous. Individual and group cognitive-behavioural therapy, supportive psychotherapy, psychodynamic therapy, family therapy and interpersonal therapy have shown benefit in subpopulations, often targeting specific elements such as grief, trauma or role transitions. ^[4] A sensitive, trauma-informed clinician matters. ^[4] A systematic review of psychological and pharmacological treatments for adjustment disorder in adults found 29 studies, mostly of low quality, and concluded that the evidence for positive effects of both psychological and pharmacological treatments on symptoms was low; most studies were of psychological rather than pharmacological treatments. ^[4]

Pharmacotherapy has a limited role. ^[4] Antidepressants have some success, but have a stronger evidence base if the final diagnosis is major depression or an anxiety disorder rather than adjustment disorder. ^[4] Benzodiazepines are often used for insomnia and anxiety but evidence is mixed, and they carry risks of dependence, misuse and acute cognitive worsening. ^[4] Other agents and supplements have been tried without evidence of efficacy. ^[4] Where distress is severe or suicidal, treat the symptom and refer urgently as for major depression, but avoid defaulting to an antidepressant without reassessing the diagnosis. ^[2][4]

MSD reviewed guidance (Merck Manual, April 2026 edition) and the DSM-5-TR stressor-focused framework are the closest available references; NICE NG222 does not cover adjustment disorder specifically, and this page therefore does not attribute adjustment treatment to NICE. ^[2][4]

• Emergency or same-day referral for acute suicidal intent or plan, psychosis, catatonia, severe self-neglect or inability to care for dependants. ^[2][4]
• Specialist assessment for a first episode in a young person; severe, psychotic or chronic features; treatment resistance after two adequate trials; suspected bipolar disorder; and pregnancy-related decisions. ^[2]
• In PDD, refer when symptoms persist despite optimised first-line treatment, when augmentation or neuromodulation is being considered, or when comorbid personality disorder dominates the picture. ^[2][3]
• In adjustment disorder, refer urgently for suicide risk, and when the diagnosis is uncertain, the stressor is ongoing and unsafe, or a fuller depressive, anxious or trauma-related syndrome emerges. ^[4]

PDD. Functional and social impairment can be as great as or greater than in MDD, and symptoms are much less likely to fully resolve in a given period. ^[1] Suicide risk is elevated, and especially so with comorbid sleep disturbance and childhood adversity. ^[1] Substance use disorders and personality disorder are common comorbidities. ^[1]

Adjustment disorder. There is an increased risk of suicide attempts and completed suicide. ^[4] Many patients maintain an adjustment disorder diagnosis or are diagnosed with another mental health disorder months to years later. ^[5] Adjustment disorder can progress to or unmask major depressive disorder, anxiety disorders or substance misuse, and readmission rates may be higher than for other mood disorders. ^[4][5] Physical health conditions (infection, cancer, Parkinson disease and cardiovascular events in the one large review) may also occur at higher rates than in controls. ^[5]

PDD. The prognosis is similar to, if not worse than, major depressive disorder; PDD independently predicts greater severity of depression, anxiety and somatic symptoms at 10-year follow-up. ^[1] Episodic major depression has a better chance of remission. About 20 to 30% of people with a major depressive episode follow a chronic course, placing them effectively in this category. ^[3]

Adjustment disorder. It is usually time-limited and mild compared with major depression: patients tend to show symptom improvement at higher rates and to use less treatment. ^[5] In the systematic review of 31 studies, 47 to 55% of patients responded to treatment. ^[5] However, AD can transition to more severe mental health states, so reassess if symptoms persist beyond six months after the stressor ends, if a fuller depressive or anxiety syndrome emerges, or if a persistent stressor continues. ^[4][5]

NICE and CANMAT agree that screening is best targeted at people with risk factors, in settings that can assess and treat, rather than applied routinely to average-risk adults. ^[2][3]

• For PDD, prevention means identifying and supporting children and adults with early adversity, trauma, chronic physical illness, bereavement and social adversity. ^[1][3] Use validated tools: the two-item screen (PHQ-2, score 2 or more positive), followed, if positive, by the PHQ-9 (score 10 or more significant). ^[3] A positive screen is not a diagnosis. ^[2][3]
• For adjustment disorder, prevention rests on timely psychosocial support after known stressors, mobilising family and workplace supports, maintaining safety and routine, and reassessment if symptoms persist. ^[4] A validated tool for ICD-11 adjustment disorder, the International Adjustment Disorder Questionnaire, exists. ^[4]
• Sleep and lifestyle are part of prevention for both: sleep disturbance and PDD interact to raise suicide risk, and healthy routine, activity and social contact support recovery. ^[1][4]

Children and adolescents. PDD can be diagnosed after one year rather than two, and often signals trauma or family adversity. ^[1] For this age group, cognitive behavioural therapy or interpersonal psychotherapy is suggested, with insufficient evidence for or against SSRI use. ^[1] Adjustment disorder occurs in young people, where stressors often involve school, family or social changes; conduct features may dominate.

Pregnancy. Depression in this period is common. Apply the general perinatal depression principles in NICE and CANMAT: psychological therapies (CBT, interpersonal therapy) are particularly suitable, use the lowest effective dose if medication is needed, avoid paroxetine and venlafaxine where possible, do not stop antidepressants abruptly, and do not use esketamine due to embryo-fetal toxicity. ^[2] Persistent symptoms require specialist involvement.

Older adults. Depression is under-recognised and may present with cognitive or somatic symptoms. Use lower starting doses, slower titration, lower anticholinergic burden and close monitoring for falls, fractures and hyponatraemia. ^[2] Physical illness, bereavement and social loss are frequent stressors for both PDD and adjustment in this age group. ^[2][4]

Low-resource settings. Non-specialists can recognise and manage most of this. For PDD, problem-solving therapy, behavioural activation and a single affordable antidepressant, delivered with community health workers and follow-up, are a realistic minimum; basic tests (CBC and TSH) exclude common mimics. ^[1][3] For adjustment disorder, assessment of the stressor, safety planning, brief supportive counselling, mobilising family and social support and monitoring for progression to major depression are the core. ^[4]

• PDD is chronic depressed mood most of the day, most days, for at least two years (one year in children and adolescents), plus at least two of six associated symptoms and impairment; no symptom-free gap of more than two months in that period. ^[1]
• PDD folded the old entities dysthymia and chronic major depression into one category; DSM-5-TR then added chronic and partially remitted major episodes as subtypes. ^[1][3]
• Its 12-month prevalence is estimated at approximately 0.5% for dysthymia and 1.5% for chronic major depression; roughly 20 to 30% of people with a major depressive episode follow a chronic course. ^[1][3]
• Cyclothymia, not PDD, is the diagnosis when hypomanic symptoms that fall short of a hypomanic episode accompany at least two years of depressed mood. ^[1]
• A history of mania or hypomania excludes PDD. ^[1]
• Adjustment disorder follows an identifiable stressor, starts within three months, causes marked distress or impairment, and remits within six months of the stressor ending. ^[4]
• Neither condition has a laboratory test; the assessment is clinical, with collateral history, risk assessment and a modest set of exclusion tests (CBC, TSH, other tests only if indicated). ^[1][3]
• PHQ-2 (positive at 2 or more) followed by PHQ-9 (significant at 10 or more) is the common screening sequence, with a PHQ-9 score of 16 or more marking more severe depression in NICE NG222. ^[2][3]
• PDD is treated as chronic depression: SSRI/SNRI, behavioural/CBASP psychotherapy, and their combination (which produces higher response and functioning than either alone), with a long continuation phase. ^[1][2]
• Adjustment disorder is treated with psychotherapy and self-care; drugs are not first-line, antidepressants have some success only if a depressive or anxiety disorder coexists, and benzodiazepines carry dependence and cognition risks. ^[4]
• Adjustment disorder carries a real suicide risk and can convert to or reveal major depression, anxiety or substance use; reassess if symptoms outlast six months after the stressor ends. ^[4][5]
• Sleep disturbance compounds suicide risk in PDD; children, who require only one year of symptoms, need trauma-informed care and have insufficient SSRI evidence. ^[1]

• Major depressive disorder
• Bipolar disorder
• Anxiety disorders
• Post-traumatic stress disorder
• Grief and prolonged grief disorder
• Suicide prevention
• Depressive disorder in older adults
• Perinatal mental health
• Substance use disorders