Depression

What is depression?

Depression is a mood disorder characterized by long-term feelings of sadness, hopelessness, or low mood. It’s one of the most common mood disorders in the world, thought to affect around 5% of adults worldwide.^[1] Depression symptoms can range from mild to severe. Mild depression might pass on its own after a short while, but if depression is left untreated it can become more severe. Severe depression can be life-threatening due to the increased risk of suicide.

It’s often thought that depression is caused by an imbalance in brain chemistry, but this isn’t always the case – depression doesn’t always have an obvious cause. Sometimes people can become depressed with otherwise normal brain chemistry or without any clear triggering events.

Who gets depression?

Depression can affect anyone at any time, but it’s more commonly seen in adults than children or teenagers. It’s also the most common mood disorder, with estimates suggesting that between 5%-17% of the general population will experience it at some point. Women are also around twice as likely to get depression than men, though it’s not fully understood why this is.^[2]

You’re also more likely to get depression if you also have an existing mood disorder like bipolar, schizophrenia, or anxiety.^[3]

Are there different types of depression?

Yes, depression can vary by type and differ from person to person. It’s more like an umbrella term for a variety of different forms, each with its own triggers, symptom patterns, and unique quirks. Understanding the specific type can make a considerable difference when it comes to finding the right treatment, too.

The most common types of depression are:

• Major depressive disorder (MDD). This is what people usually mean when they say ‘clinical depression’. It’s characterized by a persistent, overwhelming feeling of sadness, hopelessness, and a loss of interest in previously-enjoyed activities. To be diagnosed with MDD, symptoms need to last for at least two weeks and significantly interfere with daily life.
• Persistent depressive disorder (PDD). Formerly known as dysthymia, this is a chronic, long-term form of depression. The symptoms of PDD may not be as severe as MDD, but they stick around for a long time (at least two years for adults). People with PDD often feel like they’re just ‘naturally pessimistic’ or ‘functional but joyless’.
• Antenatal/Postnatal depression. These go beyond the temporary ‘baby blues’ that many new mothers get. Antenatal depression involves major depressive symptoms during pregnancy, and postnatal depression occurs after childbirth. It’s driven by hormone shifts, exhaustion, and the pressure of new parenthood, making it difficult for parents to care for themselves or their children.
• Seasonal affective disorder (SAD). SAD is a type of depression that’s linked to changes in seasons, typically starting in late fall and clearing up by spring. It’s heavily tied to the lack of natural sunlight, which disrupts your body’s internal clock and serotonin levels.
• Premenstrual dysphoric disorder (PMDD). This is a severe, sometimes debilitating form of premenstrual syndrome (PMS). It triggers severe depression, irritability, and anxiety in the week or two before your menstrual period starts, and typically resolves within a few days of onset.
• Situational depression. This happens when you’re having trouble coping with a major life stressor, like a divorce, the death of a loved one, losing a job, or a major change in circumstances. It looks like clinical depression, but it’s directly tied to a specific event and usually resolves over time or as you adapt.

What causes depression?

Depression can have a range of causes, which will be dependent on your individual circumstances. In some cases it can be caused by a traumatic event, such as a bereavement or a break-up. But it can also be caused by other factors such as drug use, illness, or stress instigated by career or financial issues.

There’s also some research to suggest that you might be more likely to get depression if you have certain personality traits like being overly self-critical, or if you have a family history of it.^[1] Depression doesn’t necessarily have to have an obvious cause, and sometimes people can become depressed without fully knowing why.

What are the symptoms of depression?

Depression is typified by extended feelings of sadness or hopelessness. This can cause some knock-on psychological and physical symptoms, such as feelings of low self-esteem, guilt, irritation around others, lack of motivation, anxiousness or suicidal thoughts. Some physical symptoms might include changes in appetite or weight, lack of energy, reduced libido or difficulty sleeping.^[2]

These symptoms can then impact your social or work life, leading you to stay at home more and avoid socialising. Depression symptoms can be categorised in severity by their impact on day-to-day life. Mild depression will have some impact on everyday life, whereas more severe cases of depression will make it very difficult to get through each day.