Depression is a common mental illness that affects more than 264 million people worldwide. It is one of the leading causes of disability and one of the main contributors to the burden of disease globally. Depression can lead to suicide.^[1]https://www.who.int/news-room/fact-sheets/detail/depression Suicide is the number one leading cause of death for Australians between the ages of 15 and 44.^[2]https://www.lifeline.org.au/resources/data-and-statistics/ Depression is believed to be affecting more women than men. Nevertheless, 75% of those who die by suicide are male.^[3]https://www.who.int/news-room/fact-sheets/detail/depression

DSM-5 Depressive Disorders

The Diagnostic and Statistical Manual of Mental Disorders (DSM) is published by the American Psychiatric Association and provides a set of agreed guidelines for diagnosis. The latest edition (5th Edition) of the Diagnostic and Statistical Manual of Mental Disorders^[4]American Psychiatric Association. (2013). Depressive disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.dsm04 outlines eight different depressive disorders:

• Disruptive Mood Dysregulation Disorder (DMDD)
• Major Depressive Disorder
• Persistent Depressive Disorder (Dysthymia)
• Premenstrual Dysphoric Disorder
• Substance/Medication-Induced Depressive Disorder
• Depressive Disorder Due to Another Medical Condition
• Other Specified Depressive Disorder
• Unspecified Depressive Disorder

Disruptive Mood Dysregulation Disorder (DMDD)

Disruptive mood dysregulation disorder must begin before the age of ten, and the diagnosis should not be applied to children younger than six years of age or older than 18.

Chronic, severe, and persistent irritation is the hallmark of disruptive mood dysregulation disorder. The first clinical indication of extreme irritability is frequent temper outbursts. These outbursts, which can be verbal or behavioural, are usually triggered by frustration.

To meet diagnostic criteria, these outbursts must be frequent, repetitive for at least one year and cross at least two settings such as home and school. The prevalence of disruptive mood dysregulation disorder among children and teenagers over a 6-month to 1-year period is likely to be in the 2%–5% range. Diagnosis rates for boys are higher than for girls.^[5]American Psychiatric Association. (2013). Depressive disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.dsm04

Major Depressive Disorder

A major depressive episode is defined by a duration of at least two weeks of low mood or a lack of interest or pleasure in almost all activities. Rather than feeling sad, children and teenagers may feel irritable.

To meet diagnostic criteria, the individual also needs to present at least three (or four if only one of the two previously described symptoms is present) of these symptoms:

• Changes in appetite or weight
• Sleep disturbances
• Unusual psychomotor activity(feeling restless or slowed down)
• Decreased energy
• Feelings of worthlessness or guilt
• Difficulties in thinking, concentrating, or making decisions;
• Repeated thoughts of death or suicidal ideation or suicide plans or attempts.

The symptoms must last for at least two weeks, the majority of the day, and almost every day. Severe distress or impairment in social, occupational, or other crucial areas of functioning must accompany the episode.

There is almost always a loss of interest or pleasure, at least to some extent. Individuals may experience a loss of interest in hobbies, a sense of “not caring anymore,” or a lack of enjoyment in formerly rewarding activities.

There can be a dramatic drop in sexual interest or desire in certain people.

Changes in appetite can be either a decrease or an increase, and sleep disturbances can manifest themselves as either difficulty sleeping or sleeping too much.

Major depressive disorder is linked to a high rate of mortality, much of which is due to suicide. Suicide attempts are more common among women, although suicide completion is less common.

Suicide attempts in the past are the most commonly mentioned risk factor. Male sex, being single or living alone, and having strong sentiments of hopelessness are all connected with an increased chance of completed suicide.^[6]American Psychiatric Association. (2013). Depressive disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.dsm04

The 12-month prevalence of major depressive disorder vary across countries, but it is estimated to be about 6%. Nevertheless, the lifetime risk of developing Major Depressive Disorder is three times higher, with almost one in five experiencing the disorder at some point in their life.^[7] Malhi, G. S., & Mann, J. J. (2018). Depression. The Lancet (British Edition), 392(10161), 2299–2312. https://doi.org/10.1016/S0140-6736(18)31948-2

The prevalence in 18- to 29-year-olds is three times greater than the prevalence in those aged 60 and over. Beginning in early adolescence, females have 1.5- to 3-fold greater rates than boys.

Heritability is estimated to be around 40%, with neuroticism accounting for a significant percentage of this genetic liability. ^[8]American Psychiatric Association. (2013). Depressive disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.dsm04

Another article outlines three times increased risk of developing Major Depressive Disorder if a first-degree relative was previously diagnosed.^[9] Malhi, G. S., & Mann, J. J. (2018). Depression. The Lancet (British Edition), 392(10161), 2299–2312. https://doi.org/10.1016/S0140-6736(18)31948-2

Furthermore, environmental factors, such as physical, sexual or emotional abuse during childhood, are strongly associated with the risk of developing Major Depressive Disorder.^[10]Otte, C., Gold, S. M., Penninx, B. W., Pariante, C. M., Etkin, A., Fava, M., … & Schatzberg, A. F. (2016). Major depressive disorder. Nature reviews Disease primers, 2(1), 1-20. … Continue reading

Other risks include loss of employment, bereavement, and separation.^[11] Malhi, G. S., & Mann, J. J. (2018). Depression. The Lancet (British Edition), 392(10161), 2299–2312. https://doi.org/10.1016/S0140-6736(18)31948-2

Treatment primarily comprises counselling or psychotherapy and pharmacological treatment. For treatment-resistant individuals who have not responded to several augmentations or combinations of treatments, electroconvulsive therapy is still in use due to its long-standing empirical evidence.^[12]Otte, C., Gold, S. M., Penninx, B. W., Pariante, C. M., Etkin, A., Fava, M., … & Schatzberg, A. F. (2016). Major depressive disorder. Nature reviews Disease primers, 2(1), 1-20. … Continue reading

With treatment, depressive episodes usually last 3-6 months. More than half of patients recover within six months, and nearly three-quarters recover within a year of treatment. Nevertheless, 27% of people, unfortunately, do not recover and develop Persistent depressive disorder.^[13] Malhi, G. S., & Mann, J. J. (2018). Depression. The Lancet (British Edition), 392(10161), 2299–2312. https://doi.org/10.1016/S0140-6736(18)31948-2

Persistent Depressive Disorder (Dysthymia)

A gloomy mood that lasts for most of the day, on more days than not, for at least two years, or at least one year for children and adolescents, is the hallmark of persistent depressive disorder (dysthymia). 

Major depression can come before persistent depressive disorder, and major depressive episodes can present during the condition. Individuals with symptoms that fulfil major depressive disorder criteria for at least two years should be diagnosed with both persistent and major depressive disorder.^[14]American Psychiatric Association. (2013). Depressive disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.dsm04

In Australia, the latest National Survey of Mental Health and Wellbeing revealed that the 12-month prevalence of persistent depressive disorder is 1 per cent for males and 1.5 per cent for females for chronic major depressive disorder.^[15]https://www.abs.gov.au/statistics/health/mental-health/national-survey-mental-health-and-wellbeing-summary-results/2007

Premenstrual Dysphoric Disorder

The expression of mood lability, irritability, dysphoria, and anxiety symptoms that occur regularly throughout the premenstrual phase of the cycle and diminish around the advent of menses or shortly thereafter are the key hallmarks of premenstrual dysphoric disorder. Behavioural and physical issues may accompany these symptoms. Symptoms must have appeared in the majority of menstrual cycles in the previous year, and they must have had a negative impact on job or social functioning.

Symptoms usually peak around the time of menstruation. Although symptoms are prevalent in the first few days of menstruation, the individual must have a symptom-free period in the follicular phase once the menstrual period starts. While mood and anxiety symptoms are the most common, behavioural and physical problems are also common. The presence of somatic and/or behavioural symptoms in the absence of mood and/or anxiety symptoms, on the other hand, is not enough to make a diagnosis. Symptoms are equivalent to those of another mental condition, such as a severe depressive episode or generalised anxiety disorder, in terms of severity (but not duration). Daily prospective symptom ratings for at least two symptomatic cycles are necessary to confirm a provisional diagnosis.

Premenstrual dysphoric condition affects 1.8 per cent to 5.8% of menstruation women over the course of a year.^[16]American Psychiatric Association. (2013). Depressive disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.dsm04

Substance/Medication-Induced Depressive Disorder

Stimulants, steroids, l-dopa, antibiotics, central nervous system pharmaceuticals, dermatological agents, chemotherapeutic drugs, and immunological therapies are examples of medications that might cause depressive mood.  

The name of the substance/medication-induced depressive disorder starts with the substance that is thought to be generating the depressive symptoms (e.g., cocaine, dexamethasone). 

The symptoms of a depressive disorder, such as major depressive disorder, are present in substance/medication-induced depressive disorder; however, the depressive symptoms are linked to the ingestion, injection, or inhalation of a substance (e.g., a drug of abuse, toxin, psychotropic medication, or other medication), and the depressive symptoms last longer than expected. The relevant depressive disorder should have arisen during or within one month following the use of a substance capable of inducing the depressed disorder, as demonstrated by clinical history, physical examination, or laboratory data. 

To qualify for this diagnosis, the depressive illness caused by substance use, intoxication, or withdrawal must cause clinically significant impairment or distress in occupational, social or other essential areas of functioning. 

The lifetime prevalence of substance/medication-induced depressive disorder is 0.26 per cent in a nationally representative adult population in the United States.^[17]American Psychiatric Association. (2013). Depressive disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.dsm04 Unfortunately, Australian statistics for this kind of depression are not available. Nevertheless, O’Brien S et al. (2007) reported that 27% of the national sample who reported drug dependence also reported depression.^[18]O’Brien S et al., National Drug and Alcohol Research Centre, Australian drug trends 2006: Findings from the Illicit Drug Reporting System (IRDS) (2007), pp 140, 151. … Continue reading And in Australia, the latest National Survey revealed that the 12-month prevalence of drug use disorder is 2.1 per cent for males and 0.8 per cent for females.^[19]https://www.abs.gov.au/statistics/health/mental-health/national-survey-mental-health-and-wellbeing-summary-results/2007

Depressive Disorder Due to Another Medical Condition

A prominent and persistent period of depressed mood or significantly diminished interest or pleasure in all, or almost all, activities that predominate in the clinical picture and need to be related to the direct physiological effects of another medical condition for someone to be diagnosed with depressive disorder due to another medical condition. The clinician must first confirm the presence of a general medical problem before assessing if the mood disturbance is attributable to a medical disease. Furthermore, the clinician must show that the mood disturbance is caused by a physiological mechanism that is linked to the overall medical condition. This decision demands a thorough and thorough examination of a variety of issues.

Although there are no foolproof rules for assessing whether the association between mood disturbance and the general medical state is etiological, there are a few things to keep in mind. The occurrence of a temporal relationship between the beginning, worsening, or remission of the general medical condition and the mood disorder is one factor to evaluate. The presence of traits that are not typical of basic Mood Disorders is a second factor to evaluate (e.g., atypical age at onset or course or absence of family history). Evidence from the literature that demonstrates a direct link between the general medical condition in issue and the onset of mood symptoms can be helpful in assessing a specific case.^[20]American Psychiatric Association. (2013). Depressive disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.dsm04 

Other Specified Depressive Disorder

This category includes cases in which depressive disorder symptoms predominate and cause clinically significant impairment or distress in occupational, social, or other important areas of functioning, but do not meet in full the necessary criteria for any of the disorders in the depressive disorders diagnostic class, nor do they meet the criteria for adjustment disorder with depressed mood. When the doctor decides to express the precise reason that the presentation does not fulfil the criteria for any specific depressive disorder, the other specified depressive disorder category is utilised. This is accomplished by writing “other specified depressive disorder” followed by the explanation (for example, “short-duration depressed episode”).

The following are some examples of presentations that can be specified using the “other specified” designation:

Recurrent brief depression: The presence of a depressed mood and at least four other depression symptoms for 2–13 days at least once a month (not associated with the menstrual cycle) for at least 12 months in an individual whose presentation has never met the criteria for any other depressive or bipolar disorder and who does not currently meet criteria for any psychotic disorder.

Short-duration depressive episode (4–13 days): Depressed affect and at least four of the other eight symptoms of a major depressive episode which are associated with clinically significant distress or impairment that lasts more than four days but less than two weeks in an individual whose presentation has never met full criteria for any of the other depressive or bipolar disorders, and who does not currently meet active or inactive criteria for any other depressive or bipolar disorder.

Depressive episode with insufficient symptoms: Depressed affect is present together with at least one of the other eight clinical symptoms of a major depressive episode associated with significant distress or impairment that persevere for at least two weeks in a person for whom the presentation has never met the criteria for bipolar disorder or any other depressive disorder.^[21]American Psychiatric Association. (2013). Depressive disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.dsm04 

Unspecified Depressive Disorder

This category refers to cases in which symptoms of a depressive disorder predominate and create significant distress or impairment in important areas of functioning but do not meet the complete criteria for any disorder in the depressive disorders diagnostic class, nor do they meet the criteria for adjustment disorder with depressed mood. The nonspecific depressive disorder category is used when the physician does not want to describe why the criteria for a specific depressive disorder have not been satisfied, and it covers presentations for which there is insufficient evidence to conclude a more specific diagnosis (e.g., in an emergency room).^[22]American Psychiatric Association. (2013). Depressive disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.dsm04 

Unspecified Depressive Disorder

This category refers to cases in which symptoms of a depressive disorder predominate and create significant distress or impairment in important areas of functioning but do not meet the complete criteria for any disorder in the depressive disorders diagnostic class, nor do they meet the criteria for adjustment disorder with depressed mood. The nonspecific depressive disorder category is used when the physician does not want to describe why the criteria for a specific depressive disorder have not been satisfied, and it covers presentations for which there is insufficient evidence to conclude a more specific diagnosis (e.g., in an emergency room).^[23]American Psychiatric Association. (2013). Depressive disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.dsm04 

Additional Specifiers For Depressive Disorders 

Specifiers can provide more detailed information about the manifestation of a depressive episode. The Diagnostic and Statistical Manual of Mental Disorders (DSM) outlines different specifiers for depressive disorders:

With anxious distress

During most days of a severe depressive episode or persistent depressive disorder (dysthymia), anxious distress is defined as the presence of at least two other symptoms: feeling tense, restlessness, fearfulness, concentration problems due to worry or fear of losing personal control and agency.

With mixed features

The depressive episode is accompanied most days by at least three manic/hypomanic features such as elevated mood, grandiosity, talkativeness, and reduced need for sleep.

With melancholic features

This specifier applies if there is either loss of pleasure in about all activities or absence of reactivity to normally pleasurable stimuli (which means that the individual is unable to experience pleasure). Furthermore, three or more other principles need to be present, including profound despair, morning downs, early awakening, psychomotor abnormalities, extreme feelings of guilt and weight loss.

With atypical features

This specifier can apply if there is mood reactivity (which means that the individual does experience relief from depression if something good happens) and two or more of these symptoms: increased appetite, hypersomnia, heaviness of limbs, and high sensitivity to rejection which affect social or working life.

With psychotic feature

This specifier can apply if the individual experiences delusions or hallucinations.

With peripartum onset

This specifier applies to women who experience depression during pregnancy or up to four weeks after giving birth. Between 3 and 6% of women will experience a major depressive episode either during pregnancy or after delivery.

Often referred to as postpartum depression, the clinical diagnosis nowadays would be called Major Depressive Disorder with Peripartum Onset.

With seasonal pattern

This applies when a relationship between depressive episodes and a particular season of the year is being observed. Fall or winter, for instance. This pattern needs to be observed for at least two years, and it is usually characterised by hypersomnia, weight gain, carbohydrates cravings and decreased energy.

This type of depression was formerly known as Seasonal Affective Disorder, or SAD; today, the official diagnosis would be Major Depressive Disorder with a Seasonal Pattern.^[24]American Psychiatric Association. (2013). Depressive disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.dsm04 

Conclusion

Nowadays, there are so many treatments available for depression. More than half of those receiving treatment recover within six months, and about three-quarters recover within a year.^[25] Malhi, G. S., & Mann, J. J. (2018). Depression. The Lancet (British Edition), 392(10161), 2299–2312. https://doi.org/10.1016/S0140-6736(18)31948-2 Help is available; reach out. If you would like to see a psychologist, your GP can provide a referral. You can also discuss with your GP about pharmaceutical options to discuss their appropriateness. If you are interested in counselling for depression with me, please visit my counselling page to read more about the process.