Major depression

Also known as: clinical depression, depression, unipolar depression.

Major depression is when you feel sad, down or miserable most of the time. You might also lose interest in things you usually enjoy.

Types of major depression include melancholia, psychotic and antenatal or postnatal. You may be diagnosed with mild, moderate or severe depression.

Dysthymic disorder

Dysthymia is long-term depression which lasts at least 2 years. It has similar symptoms to major depression, but they’re less severe.

Reactive depression

If your doctor thinks that your depression was triggered by difficult events in your life, such as divorce or money worries, they may say that it is reactive.

Bipolar disorder or Manic depression

Bipolar disorder is when you experience periods of depression and periods of mania, with periods of normal mood in between. It affects around 2 per cent of Australians and can be difficult to diagnose.

Mania

Feeling manic is the opposite of feeling depressed. In a period of mania you might:

• feel great
• have lots of energy (and not sleep much)
• have racing thoughts and talk quickly
• find it hard to focus on tasks
• feel frustrated and irritable.

Some people with bipolar can lose touch with reality and have an episode of psychosis during a period of mania. Psychosis can involve hallucinations, delusions and paranoia.

Diagnosing bipolar disorder

Diagnosis depends on you having had episodes of mania as well as episodes of depression. Because people often only seek support when they’re having an episode of depression, bipolar can be hard to diagnose.

If you’re experiencing periods of high mood as well as periods of low mood, tell your health professional when you seek support.

Sometimes it can take years to get a diagnosis of bipolar disorder. Bipolar disorder can be misdiagnosed as depression, alcohol or drug abuse, attention deficit hyperactivity disorder (ADHD) or schizophrenia.

Causes of bipolar disorder

Bipolar disorder seems to be most closely linked to family history. Stress and conflict can trigger periods of depression or mania.

Cyclothymic disorder

Cyclothymic disorder is similar to bipolar disorder but less severe. It’s a long-term condition lasting for at least 2 years.

If you have cyclothymia your periods of mania and depression are milder and shorter. In between these periods you may feel ‘normal’ for up to 2 months.

Seasonal affective disorder (SAD)

SAD is a mood disorder that has a seasonal pattern. The most common type of SAD is when you feel depressed in the winter and better in the lighter and warmer months.

When you feel depressed and have SAD you’re more likely to:

• experience a lack of energy
• sleep too much
• overeat and gain weight
• crave for carbohydrates.

SAD is thought to be related to the variation in light exposure in different seasons. It’s usually diagnosed after you’ve had the same symptoms during winter for a couple of years.

Psychotic depression

Sometimes depression can include losing touch with reality or experiencing psychosis.

Symptoms of psychotic depression can include hallucinations, delusions and paranoia.

Hallucinations

You might see or hear things that aren’t there.

Delusions

A delusion is a false belief that isn’t shared by others. For example, you might believe that you’re:

• bad or evil
• being watched or followed.

Paranoia

If you feel paranoid you might:

• feel like everyone is against you
• believe that other people have made you ill or caused bad things to happen

Antenatal and postnatal depression

Your risk of developing depression is higher during pregnancy and in the first year after childbirth. During pregnancy around 10 per cent of women experience depression. In the first three months after having a baby this increases to 16 per cent.

Depression which develops during pregnancy and after childbirth has a few different names:

• antenatal or prenatal depression – depression during pregnancy
• postnatal depression – depression in the year after childbirth
• perinatal depression – any time during pregnancy or in the year after childbirth.

Around 80 per cent of women get the ‘baby blues’ in the first few days after childbirth. You might feel tearful or overwhelmed, but this will pass in a few days with care and support.

The baby blues happens because of changes in your hormones after your baby is born and doesn’t mean you’ll develop depression.

Atypical depression

“Atypical features” is a specifier that describes individual depressive episodes. While the name suggests it’s not particularly common, that’s not actually the case. The atypical name comes because of the way it differs from depression with melancholic features.

In addition to meeting the criteria for a major depressive episode, the atypical features specifier requires the first of the following symptoms as well as at least two others:

• mood reactivity to pleasurable stimuli or positive events
• increased appetite or significant weight gain (as opposed to decreased appetite and weight loss in melancholic features)
• increased sleep (as opposed to early morning awakening in melancholic features)
• feeling of heaviness in the limbs that has a significant impact on functioning (aka leaden paralysis)
• a pattern of longstanding sensitivity to interpersonal rejection

In the world of psychiatry, the term “neurovegetative symptoms” refers to depression’s impact on sleep, appetite, and weight. The increased sleep and appetite with atypical features is sometimes referred to as reversed neurovegetative symptoms (i.e. a reversed pattern from melancholic features).

Atypical features first showed up in the DSM with the release of the DSM-IV back in 1994. There’s been a fair bit of debate around the criteria and whether it constitutes a distinct illness from melancholic depression. While the DSM requires mood reactivity for an atypical features diagnosis, some researchers have argued against that.

Between 15-29% of patients with depression have atypical features. It’s particularly common in people with bipolar II disorder and persistent depressive disorder (formerly known as dysthymia). Atypical features are more common in females, and the age of onset tends to be younger than in people with other presentations of depression. Almost 2/3 of people who have atypical features in a given depressive episode have a repeat of atypical features in their next episode.

People with atypical features are more likely to have a history of sexual abuse or neglect (research results are less clear re. physical abuse) versus those with non-atypical features. They’re also more likely to experience suicidal thinking and suicide attempts, as well as greater functional disability.

People with atypical features are more likely to have comorbid conditions, and in particular panic disorder, social anxiety disorder, or bulimia, compared to people with non-atypical depression. Rates of substance abuse are also higher.

While melancholic depression often involves a hyperactive stress hormone system (the hypothalamic-pituitary-adrenal axis), that’s not the case in atypical depression, and an underactive HPA axis has been observed in some patients with reversed neurovegetative symptoms. Differences in blood perfusion to certain areas of the brain have been observed in atypical vs non-atypical depression.

Depression with Melancholic Features

The word melancholia comes from the Greek for black bile, part of the ancient four humours medical belief system. In the 5th century BCE, Hippocrates first identified melancholia as a disease with various mental and physical symptoms. In the 16th and 17th centuries, the idea of a melancholic temperament became fashionable in English art and literature.

Past names for depression with melancholic features include endogenous (vs. reactive) depression and melancholia.

Diagnosis

In the DSM-5, the melancholic features specifier can be used to describe a major depressive episode (in major depressive disorder or bipolar disorder) with a certain cluster of symptoms. That symptom cluster includes:

1. anhedonia (near-total inability to feel pleasure)
2. lack of positive reaction to normally pleasurable things
3. a quality of mood that’s distinct from grief/loss, i.e. it subjectively feels different
4. early morning awakening
5. psychomotor retardation (slowed movement and thinking) or agitation
6. significant loss of appetite
7. symptoms that are worse in the morning
8. excessive/inappropriate guilt

Either symptom #1 or 2 must be present, in addition to at least 3 symptoms from #3-8. Symptom #5 (psychomotor changes) is nearly always present. The full criteria for a major depressive episode must be met, including the presence of symptoms almost all day, almost every day, for at least 2 weeks, with clinically significant distress or impairment in social and occupational functioning.

While many people experiencing a major depressive episode experience some of these symptoms, this particular symptom cluster occurring together is what constitutes melancholic features. There are many different potential combinations of symptoms in a major depressive episode, and not everyone who’s having a major depressive episode has a features specifier of any kind.

There’s some question as to whether melancholic depression represents a distinct illness from depression with atypical features, which involves a cluster of symptoms like increased sleep and appetite, mood reactivity to pleasurable stimuli, and leaden paralysis. At this point, though, the DSM’s categorical system treats them as different features of the same illness.

The biology of melancholia

There do appear to be differences in how melancholic depression affects the brain, including changes that can be seen on electroencephalogram (EEG) and MRI across groups of patients with melancholic vs. non-melancholic depression.

Melancholic depression appears to have a strong biological component, including a genetic element. There appear to be disruptions in the hypothalamic-pituitary-adrenal (HPA) axis that connects the brain and the adrenal glands, as well as elevated inflammation.

Despite these elements that researchers have observed across groups of patients, science hasn’t yet come up with a biological feature that’s a definite diagnostic marker.

Characteristics of melancholic depression

People with melancholic features tend to have relatively normal childhoods, and when well, they tend not to have significant problems with relationships and work functioning. The depression is more likely to be identified as an imposed illness rather than a logical reaction to life stressors.

Episodes can occur with no apparent situational triggers, and they tend to be more severe than one might expect given the situational circumstances. Melancholic episodes can also occur in response to minor, non-severe stressors, and researchers from Queen’s University have suggested that melancholic depression may be especially sensitive to stress. This would fit with the idea of inflammation playing some role in this particular form of depression.

The Lundby Study, a longitudinal community-based study in Sweden, showed that people whose first depressive episode had melancholic features were at a greater risk for recurrence of their depression compared to people with a non-melancholic first depressive episode.

Cognitive dysfunction

Melancholic features have been associated with greater cognitive dysfunction than non-melancholic depression, including poorer processing speed, problem-solving, and visual memory. Psychotic features are also more common in this form of depression.

Reward system

Researchers have observed deficits in reward-based learning tasks, meaning people are less likely to develop behaviours geared towards maximizing rewards. This may be related to dysfunction in dopamine signalling in the brain’s reward areas.

Response to treatment

Melancholic depression tends to respond better to biological treatments like antidepressants and electroconvulsive therapy (ECT) than it does to psychotherapy, and it’s less responsive to placebo than other forms of depression.

Some research has shown an improved response to antidepressants that target multiple neurotransmitter systems rather than just serotonin, although there have been contradictory findings. In keeping with this, some studies have suggested that tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs) may be the most effective. It can sometimes be helpful to add other medications to augment antidepressants, including atypical antipsychotics or psychostimulants (e.g. Ritalin, Dexedrine).

Getting personal

My own symptom pattern tends toward melancholic features, although not always. The anhedonia and psychomotor retardation are pretty prominent. I get the early morning awakening, decreased appetite, and guilt, but they’re usually kept under control when I’m well-medicated. I’ve never had atypical features to my depression, and when my sleep and appetite are affected, they’re always decreased, not increased.