What is Hyperthymic Temperament?

Introduction

Hyperthymic temperament, or hyperthymia, from Ancient Greek ὑπέρ (“over”, meaning here excessive) + θυμός (“spirited”), is a proposed personality type characterised by an exceptionally, or in some cases, abnormally positive mood and disposition.

Also known as Hyperthymic Personality-Type and Chronic Hypomania.

Refer to Bipolar Disorder.

Graph showing showing hyperthymia in comparison to other bipolar spectrum disorders.

Background

It is generally defined by increased energy, vividness and enthusiasm for life activities, as opposed to dysthymia. Hyperthymia is similar to but more stable than hypomania.

Characteristics of the hyperthymic temperament include:

  • Increased energy and productivity.
  • Short sleep patterns.
  • Vividness, activity extroversion.
  • Self-assurance, self-confidence.
  • Strong will.
  • Extreme talkativeness.
  • Tendency to repeat oneself.
  • Risk-taking/sensation seeking.
  • Breaking social norms.
  • Very strong libido.
  • Love of attention.
  • Low threshold for boredom.
  • Generosity and tendency to overspend.
  • Emotion sensitivity.
  • Cheerfulness and joviality.
  • Unusual warmth.
  • Expansiveness.
  • Tirelessness.
  • Irrepressibility, irresistible, and infectious quality.

The clinical, psychiatric understanding of hyperthymia is evolving. Studies have shown that hyperthymic temperament promotes efficient performance of complex tasks under time pressure or extreme conditions. Despite this positive characterisation, hyperthymia can be complicated with depressive episodes manifesting as a softer form of bipolar illness, such as cyclothymia. Research also suggests a familial genetic connection of the temperament to bipolar I.

Aside from references in historical and more recent writings on the spectrum of mood disorders, further literature on the temperament is lacking. There is a lack of agreement on its definition, implications or whether it is pathological. It is not known where to place hyperthymia on the affective spectrum.

Hyperthymia manifesting intermittently or in an unusual way may mask hypomania or another psychiatric disorder. Hyperthymia can be most accurately diagnosed by a psychologist or psychiatrist with the help of a patient’s family and/or close friends.

What is Depressive Personality Disorder?

Introduction

Depressive personality disorder (also known as melancholic personality disorder) is a psychiatric diagnosis that denotes a personality disorder with depressive features.

Originally included in the American Psychiatric Association’s DSM-II, depressive personality disorder was removed from the DSM-III and DSM-III-R. Recently, it has been reconsidered for reinstatement as a diagnosis. Depressive personality disorder is currently described in Appendix B in the DSM-IV-TR as worthy of further study. Although no longer listed as a personality disorder, the diagnosis is included under the section “personality disorder not otherwise specified”.

While depressive personality disorder shares some similarities with mood disorders such as dysthymia, it also shares many similarities with personality disorders including avoidant personality disorder. Some researchers argue that depressive personality disorder is sufficiently distinct from these other conditions so as to warrant a separate diagnosis.

Characteristics

The DSM-IV defines depressive personality disorder as “a pervasive pattern of depressive cognitions and behaviors beginning by early adulthood and occurring in a variety of contexts.” Depressive personality disorder occurs before, during, and after major depressive episodes, making it a distinct diagnosis not included in the definition of either major depressive episodes or dysthymic disorder. Specifically, five or more of the following must be present most days for at least two years in order for a diagnosis of depressive personality disorder to be made:

  • Usual mood is dominated by dejection, gloominess, cheerlessness, joylessness and unhappiness.
  • Self-concept centres on beliefs of inadequacy, worthlessness and low self-esteem.
  • Is critical, blaming and derogatory towards the self.
  • Is brooding and given to worry.
  • Is negativistic, critical and judgmental toward others.
  • Is pessimistic.
  • Is prone to feeling guilty or remorseful.

People with depressive personality disorder have a generally gloomy outlook on life, themselves, the past and the future. They are plagued by issues developing and maintaining relationships. In addition, studies have found that people with depressive personality disorder are more likely to seek psychotherapy than people with Axis I depression spectra diagnoses.

Recent studies have concluded that people with depressive personality disorder are at a greater risk of developing dysthymic disorder than a comparable group of people without depressive personality disorder. These findings lead to the fact that depressive personality disorder is a potential precursor to dysthymia or other depression spectrum diagnoses. If included in the DSM-V, depressive personality disorder would be included as a warning sign for potential development of more severe depressive episodes.

DSM-5

Similarities to Dysthymic Disorder

Much of the controversy surrounding the potential inclusion of depressive personality disorder in the DSM-5 stems from its apparent similarities to dysthymic disorder, a diagnosis already included in the DSM-IV. Dysthymic disorder is characterised by a variety of depressive symptoms, such as hypersomnia or fatigue, low self-esteem, poor appetite, or difficulty making decisions, for over two years, with symptoms never numerous or severe enough to qualify as major depressive disorder. Patients with dysthymic disorder may experience social withdrawal, pessimism, and feelings of inadequacy at higher rates than other depression spectrum patients. Early-onset dysthymia is the diagnosis most closely related to depressive personality disorder.

The key difference between dysthymic disorder and depressive personality disorder is the focus of the symptoms used to diagnose. Dysthymic disorder is diagnosed by looking at the somatic senses, the more tangible senses. Depressive personality disorder is diagnosed by looking at the cognitive and intrapsychic symptoms. The symptoms of dysthymic disorder and depressive personality disorder may look similar at first glance, but the way these symptoms are considered distinguish the two diagnoses.

Comorbidity with other Disorders

Many researchers believe that depressive personality disorder is so highly comorbid with other depressive disorders, manic-depressive episodes and dysthymic disorder, that it is redundant to include it as a distinct diagnosis. Recent studies however, have found that dysthymic disorder and depressive personality disorder are not as comorbid as previously thought. It was found that almost two thirds of the test subjects with depressive personality disorder did not have dysthymic disorder, and 83% did not have early-onset dysthymia.

The comorbidity with Axis I depressive disorders is not as high as had been assumed. An experiment conducted by American psychologists showed that depressive personality disorder shows a high comorbidity rate with major depression experienced at some point in a lifetime and with any mood disorders experienced at any point in a lifetime. A high comorbidity rate with these disorders is expected of many diagnoses. As for the extremely high comorbidity rate with mood disorders, it has been found that essentially all mood disorders are comorbid with at least one other, especially when looking at a lifetime sample size.

What is Dysthymia?

Introduction

Dysthymia, also known as persistent depressive disorder (PDD), is a mental and behavioural disorder, specifically a disorder primarily of mood, consisting of the same cognitive and physical problems as depression, but with longer-lasting symptoms.

The concept was coined by Robert Spitzer as a replacement for the term “depressive personality” in the late 1970s.

In the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), dysthymia is a serious state of chronic depression, which persists for at least two years (one year for children and adolescents). Dysthymia is less acute than major depressive disorder, but not necessarily less severe.

As dysthymia is a chronic disorder, sufferers may experience symptoms for many years before it is diagnosed, if diagnosis occurs at all. As a result, they may believe that depression is a part of their character, so they may not even discuss their symptoms with doctors, family members or friends. In the DSM-5, dysthymia is replaced by persistent depressive disorder. This new condition includes both chronic major depressive disorder and the previous dysthymic disorder. The reason for this change is that there was no evidence for meaningful differences between these two conditions.

Epidemiology

Globally dysthymia occurs in about 105 million people a year (1.5% of the population). It is 38% more common in women (1.8% of women) than in men (1.3% of men). The lifetime prevalence rate of dysthymia in community settings appears to range from 3 to 6% in the United States. However, in primary care settings the rate is higher ranging from 5 to 15 percent. United States prevalence rates tend to be somewhat higher than rates in other countries.

Signs and Symptoms

Dysthymia characteristics include an extended period of depressed mood combined with at least two other symptoms which may include insomnia or hypersomnia, fatigue or low energy, eating changes (more or less), low self-esteem, or feelings of hopelessness. Poor concentration or difficulty making decisions are treated as another possible symptom. Irritability is one of the more common symptoms in children and adolescents.

Mild degrees of dysthymia may result in people withdrawing from stress and avoiding opportunities for failure. In more severe cases of dysthymia, people may withdraw from daily activities. They will usually find little pleasure in usual activities and pastimes.

Diagnosis of dysthymia can be difficult because of the subtle nature of the symptoms and patients can often hide them in social situations, making it challenging for others to detect symptoms. Additionally, dysthymia often occurs at the same time as other psychological disorders, which adds a level of complexity in determining the presence of dysthymia, particularly because there is often an overlap in the symptoms of disorders.

There is a high incidence of comorbid illness in those with dysthymia. Suicidal behaviour is also a particular problem with those with dysthymia. It is vital to look for signs of major depression, panic disorder, generalised anxiety disorder, alcohol and substance use disorders, and personality disorder.

Causes

There are no known biological causes that apply consistently to all cases of dysthymia, which suggests diverse origin of the disorder. However, there are some indications that there is a genetic predisposition to dysthymia: “The rate of depression in the families of people with dysthymia is as high as fifty percent for the early-onset form of the disorder”. Other factors linked with dysthymia include stress, social isolation, and lack of social support.

In a study using identical and fraternal twins, results indicated that there is a stronger likelihood of identical twins both having depression than fraternal twins. This provides support for the idea that dysthymia is in part caused by heredity.

Co-Occurring Conditions

Dysthymia often co-occurs with other mental disorders. A “double depression” is the occurrence of episodes of major depression in addition to dysthymia. Switching between periods of dysthymic moods and periods of hypomanic moods is indicative of cyclothymia, which is a mild variant of bipolar disorder.

“At least three-quarters of patients with dysthymia also have a chronic physical illness or another psychiatric disorder such as one of the anxiety disorders, cyclothymia, drug addiction, or alcoholism”. Common co-occurring conditions include major depression (up to 75%), anxiety disorders (up to 50%), personality disorders (up to 40%), somatoform disorders (up to 45%) and substance use disorders (up to 50%). People with dysthymia have a higher-than-average chance of developing major depression. A 10-year follow-up study found that 95% of dysthymia patients had an episode of major depression. When an intense episode of depression occurs on top of dysthymia, the state is called “double depression.”

Double Depression

Double depression occurs when a person experiences a major depressive episode on top of the already-existing condition of dysthymia. It is difficult to treat, as sufferers accept these major depressive symptoms as a natural part of their personality or as a part of their life that is outside of their control. The fact that people with dysthymia may accept these worsening symptoms as inevitable can delay treatment. When and if such people seek out treatment, the treatment may not be very effective if only the symptoms of the major depression are addressed, but not the dysthymic symptoms. Patients with double depression tend to report significantly higher levels of hopelessness than is normal. This can be a useful symptom for mental health services providers to focus on when working with patients to treat the condition. Additionally, cognitive therapies can be effective for working with people with double depression in order to help change negative thinking patterns and give individuals a new way of seeing themselves and their environment.

It has been suggested that the best way to prevent double depression is by treating the dysthymia. A combination of antidepressants and cognitive therapies can be helpful in preventing major depressive symptoms from occurring. Additionally, exercise and good sleep hygiene (e.g. improving sleep patterns) are thought to have an additive effect on treating dysthymic symptoms and preventing them from worsening.

Pathophysiology

There is evidence that there may be neurological indicators of early onset dysthymia. There are several brain structures (corpus callosum and frontal lobe) that are different in women with dysthymia than in those without dysthymia. This may indicate that there is a developmental difference between these two groups.

Another study, which used fMRI techniques to assess the differences between individuals with dysthymia and other people, found additional support for neurological indicators of the disorder. This study found several areas of the brain that function differently. The amygdala (associated with processing emotions such as fear) was more activated in dysthymia patients. The study also observed increased activity in the insula (which is associated with sad emotions). Finally, there was increased activity in the cingulate gyrus (which serves as the bridge between attention and emotion).

A study comparing healthy individuals to people with dysthymia indicates there are other biological indicators of the disorder. An anticipated result appeared as healthy individuals expected fewer negative adjectives to apply to them, whereas people with dysthymia expected fewer positive adjectives to apply to them in the future. Biologically these groups are also differentiated in that healthy individuals showed greater neurological anticipation for all types of events (positive, neutral, or negative) than those with dysthymia. This provides neurological evidence of the dulling of emotion that individuals with dysthymia have learned to use to protect themselves from overly strong negative feelings, compared to healthy people.

There is some evidence of a genetic basis for all types of depression, including dysthymia. A study using identical and fraternal twins indicated that there is a stronger likelihood of identical twins both having depression than fraternal twins. This provides support for the idea that dysthymia is caused in part by heredity.

A new model has recently surfaced in the literature regarding the HPA axis (structures in the brain that get activated in response to stress) and its involvement with dysthymia (e.g. phenotypic variations of corticotropin releasing hormone (CRH) and arginine vasopressin (AVP), and down-regulation of adrenal functioning) as well as forebrain serotonergic mechanisms. Since this model is highly provisional, further research is still needed.

Diagnosis

The Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV), published by the American Psychiatric Association, characterises dysthymic disorder. The essential symptom involves the individual feeling depressed for the majority of days, and parts of the day, for at least two years. Low energy, disturbances in sleep or in appetite, and low self-esteem typically contribute to the clinical picture as well. Sufferers have often experienced dysthymia for many years before it is diagnosed. People around them often describe the sufferer in words similar to “just a moody person”. Note the following diagnostic criteria:

  1. During a majority of days for two years or more, the adult patient reports depressed mood, or appears depressed to others for most of the day.
  2. When depressed, the patient has two or more of:
    1. decreased or increased appetite
    2. decreased or increased sleep (insomnia or hypersomnia)
    3. Fatigue or low energy
    4. Reduced self-esteem
    5. Decreased concentration or problems making decisions
    6. Feelings of hopelessness or pessimism
  3. During this two-year period, the above symptoms are never absent longer than two consecutive months.
  4. During the duration of the two-year period, the patient may have had a perpetual major depressive episode.
  5. The patient has not had any manic, hypomanic, or mixed episodes.
  6. The patient has never fulfilled criteria for cyclothymic disorder.
  7. The depression does not exist only as part of a chronic psychosis (such as schizophrenia or delusional disorder).
  8. The symptoms are often not directly caused by a medical illness or by substances, including substance use or other medications.
  9. The symptoms may cause significant problems or distress in social, work, academic, or other major areas of life functioning.

In children and adolescents, mood can be irritable, and duration must be at least one year, in contrast to two years needed for diagnosis in adults.

Early onset (diagnosis before age 21) is associated with more frequent relapses, psychiatric hospitalisations, and more co-occurring conditions. For younger adults with dysthymia, there is a higher co-occurrence in personality abnormalities and the symptoms are likely chronic. However, in older adults suffering from dysthymia, the psychological symptoms are associated with medical conditions and/or stressful life events and losses.

Dysthymia can be contrasted with major depressive disorder by assessing the acute nature of the symptoms. Dysthymia is far more chronic (long lasting) than major depressive disorder, in which symptoms may be present for as little as 2 weeks. Also Dysthymia often presents itself at an earlier age than Major Depressive Disorder.

Prevention

Though there is no clear-cut way to prevent dysthymia from occurring, some suggestions have been made. Since dysthymia will often first occur in childhood, it is important to identify children who may be at risk. It may be beneficial to work with children in helping to control their stress, increase resilience, boost self-esteem, and provide strong networks of social support. These tactics may be helpful in warding off or delaying dysthymic symptoms.

Treatment

Persistent depressive disorder can be treated with psychotherapy and pharmacotherapy. The overall rate and degree of treatment success is somewhat lower than for non-chronic depression, and a combination of psychotherapy and pharmacotherapy shows best results.

Therapy

Psychotherapy can be effective in treating dysthymia. In a meta-analytic study from 2010, psychotherapy had a small but significant effect when compared to control groups. However, psychotherapy is significantly less effective than pharmacotherapy in direct comparisons.

There are many different types of therapy, and some are more effective than others.

  • The empirically most studied type of treatment is cognitive-behavioural therapy.
    • This type of therapy is very effective for non-chronic depression, and it appears to be also effective for chronic depression.
  • Cognitive behavioural analysis system of psychotherapy (CBASP) has been designed specifically to treat PDD.
    • Empirical results on this form of therapy are inconclusive: While one study showed remarkably high treatment success rates, a later, even larger study showed no significant benefit of adding CBASP to treatment with antidepressants.
  • Schema therapy and psychodynamic psychotherapy have been used for PDD, though good empirical results are lacking.
  • Interpersonal psychotherapy has also been said to be effective in treating the disorder, though it only shows marginal benefit when added to treatment with antidepressants.

Medications

In a 2010 meta-analysis, the benefit of pharmacotherapy was limited to selective serotonin reuptake inhibitors (SSRIs) rather than tricyclic antidepressants (TCA).

According to a 2014 meta-analysis, antidepressants are at least as effective for persistent depressive disorder as for major depressive disorder. The first line of pharmacotherapy is usually SSRIs due to their purported more tolerable nature and reduced side effects compared to the irreversible monoamine oxidase inhibitors or tricyclic antidepressants. Studies have found that the mean response to antidepressant medications for people with dysthymia is 55%, compared with a 31% response rate to a placebo. The most commonly prescribed antidepressants/SSRIs for dysthymia are escitalopram, citalopram, sertraline, fluoxetine, paroxetine, and fluvoxamine. It often takes an average of 6-8 weeks before the patient begins to feel these medications’ therapeutic effects. Additionally, STAR*D, a multi-clinic governmental study, found that people with overall depression will generally need to try different brands of medication before finding one that works specifically for them. Research shows that 1 in 4 of those who switch medications get better results regardless of whether the second medication is an SSRI or some other type of antidepressant.

In a meta-analytic study from 2005, it was found that SSRIs and TCAs are equally effective in treating dysthymia. They also found that MAOIs have a slight advantage over the use of other medication in treating this disorder. However, the author of this study cautions that MAOIs should not necessarily be the first line of defence in the treatment of dysthymia, as they are often less tolerable than their counterparts, such as SSRIs.

Tentative evidence supports the use of amisulpride to treat dysthymia but with increased side effects.

Combination Treatment

When pharmacotherapy alone is compared with combined treatment with pharmacotherapy plus psychotherapy, there is a strong trend in favour of combined treatment. Working with a psychotherapist to address the causes and effects of the disorder, in addition to taking antidepressants to help eliminate the symptoms, can be extremely beneficial. This combination is often the preferred method of treatment for those who have dysthymia. Looking at various studies involving treatment for dysthymia, 75% of people responded positively to a combination of cognitive behavioural therapy and pharmacotherapy, whereas only 48% of people responded positively to just CBT or medication alone.

A 2019 Cochrane review of 10 studies involving 840 participants could not conclude with certainty that continued pharmacotherapy with antidepressants (those used in the studies) was effective in preventing relapse or recurrence of persistent depressive disorder. The body of evidence was too small for any greater certainty although the study acknowledges that continued psychotherapy may be beneficial when compared to no treatment.

Resistance

Because of dysthymia’s chronic nature, treatment resistance is somewhat common. In such a case, augmentation is often recommended. Such treatment augmentations can include lithium pharmacology, thyroid hormone augmentation, amisulpride, buspirone, bupropion, stimulants, and mirtazapine. Additionally, if the person also suffers from seasonal affective disorder, light therapy can be useful in helping augment therapeutic effects.

What is Atypical Depression?

Introduction

Atypical depression as it has been known in the DSM IV, is depression that shares many of the typical symptoms of the psychiatric syndromes of major depression or dysthymia but is characterised by improved mood in response to positive events.

In contrast to atypical depression, people with melancholic depression generally do not experience an improved mood in response to normally pleasurable events. Atypical depression also features significant weight gain or an increased appetite, hypersomnia, a heavy sensation in the limbs, and interpersonal rejection sensitivity that results in significant social or occupational impairment.

Despite its name, “atypical” depression does not mean it is uncommon or unusual. The reason for its name is twofold: it was identified with its “unique” symptoms subsequent to the identification of melancholic depression and its responses to the two different classes of antidepressants that were available at the time were different from melancholic depression (i.e. monoamine oxidase inhibitors (MAOIs) had clinically significant benefits for atypical depression, while tricyclics did not).

Atypical depression is four times more common in females than in males. Individuals with atypical features tend to report an earlier age of onset (e.g. while in high school) of their depressive episodes, which also tend to be more chronic and only have partial remission between episodes. Younger individuals may be more likely to have atypical features, whereas older individuals may more often have episodes with melancholic features. Atypical depression has high comorbidity of anxiety disorders, carries more risk of suicidal behaviour, and has distinct personality psychopathology and biological traits.

Atypical depression is more common in individuals with bipolar I, bipolar II, cyclothymia and seasonal affective disorder. Depressive episodes in bipolar disorder tend to have atypical features, as does depression with seasonal patterns.

Refer to Masked Depression and Treatment-Resistant Depression.

Pathophysiology

Significant overlap between atypical and other forms of depression have been observed, though studies suggest there are differentiating factors within the various pathophysiological models of depression. In the endocrine model, evidence suggests the HPA axis is hyperactive in melancholic depression, and hypoactive in atypical depression. Atypical depression can be differentiated from melancholic depression via verbal fluency tests and psychomotor speed tests. Although both show impairment in several areas such as visuospatial memory and verbal fluency, melancholic patients tend to show more impairment than atypical depressed patients.

Furthermore, regarding the inflammatory theory of depression, inflammatory blood markers (cytokines) appear to be more elevated in atypical depression when compared to non-atypical depression.

Diagnosis

The diagnosis of atypical depression is based on the criteria stated in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The DSM-5 defines atypical depression as a subtype of major depressive disorder that presents with “atypical features”, characterised by:

  • Mood reactivity (i.e., mood brightens in response to actual or potential positive events)
  • At least two of the following:
    • Significant weight gain or increase in appetite (hyperphagia);
    • Hypersomnia (sleeping too much, as opposed to the insomnia present in melancholic depression);
    • Leaden paralysis (i.e., heavy feeling resulting in difficulty moving the arms or legs);
    • Long-standing pattern of interpersonal rejection sensitivity (not limited to episodes of mood disturbance) that results in significant social or occupational impairment.

Criteria are not met for With Melancholic Features or With Catatonic Features during the same episode.

Treatment

Due to the differences in clinical presentation between atypical depression and melancholic depression, studies were conducted in the 1980s and 1990s to assess the therapeutic responsiveness of the available antidepressant pharmacotherapy in this subset of patients. Currently, antidepressants such as SSRIs, SNRIs, NRIs, and mirtazapine are considered the best medications to treat atypical depression due to efficacy and fewer side effects than previous treatments. Bupropion, a norepinephrine reuptake inhibitor, may be uniquely suited to treat the atypical depression symptoms of lethargy and increased appetite in adults. Modafinil is sometimes used successfully as an off-label treatment option.

Before the year 2000, monoamine oxidase inhibitors (MAOIs) were shown to be of superior efficacy compared to other antidepressants for the treatment of atypical depression, and were used as first-line treatment for this clinical presentation. This class of medication fell in popularity with the advent of the aforementioned selective agents, due to concerns of interaction with tyramine-rich foods (such as some aged cheese, certain types of wine, tap beer and fava beans) causing a hypertensive crisis and some – but not all – sympathomimetic drugs, as well as the risk of serotonin syndrome when concomitantly used with serotonin reuptake agents. Despite these concerns, they are still used in treatment-resistant cases, when other options have been exhausted, and usually show greater rates of remission compared to previous pharmacotherapies. They are also generally better tolerated by many patients. There are also newer selective and reversible MAOIs, such as moclobemide, which carry a much lower risk of tyramine potentiation and have fewer interactions with other drugs.

Tricyclic antidepressants (TCAs) were also used prior to the year 2000 for atypical depression, but were not as efficacious as MAOIs, and have fallen out of favour with prescribers due to the less tolerable side effects of TCAs and more adequate therapies being available.

Some evidence supports that psychotherapy such as cognitive behavioural therapy (CBT) has equal efficacy to MAOI. These are talk therapy sessions with psychiatrists to help the individual identify troubling thoughts or experiences that may have affected their mental state, and develop corresponding coping mechanisms for each identified issue.

No robust guidelines for the treatment of atypical depression currently exist.

Epidemiology

True prevalence of atypical depression is difficult to determine. Several studies conducted in patients diagnosed with a depressive disorder show that about 40% exhibit atypical symptoms, with four times more instances found in female patients. Research also supports that atypical depression tends to have an earlier onset, with teenagers and young adults more likely to exhibit atypical depression than older patients. Patients with atypical depression have shown to have higher rates of neglect and abuse in their childhood as well as alcohol and drug disorders in their family. Overall, rejection sensitivity is the most common symptom, and due to some studies forgoing this criterion, there is concern for underestimation of prevalence.

Research

In general, atypical depression tends to cause greater functional impairment than other forms of depression. Atypical depression is a chronic syndrome that tends to begin earlier in life than other forms of depression – usually beginning in the teenage years. Similarly, patients with atypical depression are more likely to suffer from personality disorders and anxiety disorders such as borderline personality disorder, avoidant personality disorder, generalised anxiety disorder, obsessive-compulsive disorder, and bipolar disorder.

Recent research suggests that young people are more likely to suffer from hypersomnia while older people are more likely to suffer from polyphagia.

Medication response differs between chronic atypical depression and acute melancholic depression. Some studies suggest that the older class of antidepressants, MAOIs, may be more effective at treating atypical depression. While the more modern SSRIs and SNRIs are usually quite effective in this illness, the tricyclic antidepressants typically are not. The wakefulness-promoting agent modafinil has shown considerable effect in combating atypical depression, maintaining this effect even after discontinuation of treatment. Antidepressant response can often be enhanced with supplemental medications, such as buspirone, bupropion, or aripiprazole. Psychotherapy, whether alone or in combination with medication, is also an effective treatment in individual and group settings.