What Is Depression (Major Depressive Disorder)

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Major depressive disorder, often simply called depression or clinical depression, is a common mental health condition that affects how a person feels, thinks, and functions. It goes beyond ordinary sadness or a bad week. To meet criteria, a person experiences low mood or a loss of interest or pleasure most of the day, nearly every day, for at least two weeks, along with other symptoms that affect daily life. Depression can happen to anyone, at any age, and it is not a sign of weakness. It is also one of the most treatable mental health conditions, and most people improve with the right support.

What Depression Looks Like

Diagnosis requires at least five of the following, including one of the first two:

• Low, sad, or empty mood, or irritability, most of the day.
• Loss of interest or pleasure in most activities.
• Changes in appetite or weight.
• Sleeping much less or much more than usual.
• Feeling slowed down or restless in a way others can notice.
• Fatigue or loss of energy, including days when getting out of bed feels impossible.
• Feelings of worthlessness or excessive guilt.
• Difficulty concentrating or making decisions.
• Recurring thoughts of death or suicide.

Depression can also show up through physical complaints, such as aches or digestive problems, and through withdrawal from friends and family. It may look different from person to person. Some forms involve oversleeping and mood that brightens with good news, described on the page about atypical depression. Others are hidden behind a busy, capable exterior, as explored in high-functioning depression.

Why It Happens

Depression arises from a combination of factors rather than a single cause. Genetics play a role, and depression often runs in families. Changes in brain systems involved in mood, stress, sleep, and reward are part of the picture. Life events, such as loss, relationship breakdown, financial strain, or trauma, can trigger episodes, especially when support is limited. Chronic illness, hormonal changes, some medications, and substance use can contribute. Personal factors, such as a tendency toward self-criticism or rumination, increase vulnerability.

Once depression begins, it can sustain itself. Low energy leads to doing less, which reduces pleasure and connection, which deepens low mood. Negative thinking becomes more automatic, making problems seem permanent and personal. Understanding this cycle helps explain why small, steady steps are often part of recovery.

Depression often occurs as a single episode, but it can also recur. Many people experience more than one episode over their lifetime, especially without treatment. Learning personal warning signs, such as changes in sleep or withdrawal from friends, and having a plan to act early can reduce the chance of a full relapse.

What It Is Not

• Not ordinary sadness. Sadness passes. Depression lasts, affects many areas of life, and needs attention.
• Not a character flaw or laziness. It is a health condition.
• Not something you can simply snap out of. Effort alone rarely resolves it.
• Not the same as persistent depressive disorder, which involves milder symptoms lasting at least two years, as described on the page about dysthymia.
• Not permanent. Most people recover with treatment.

How It Is Assessed and Treated

A clinician will ask about symptoms, their duration and severity, life circumstances, history, and safety. A physician may check for medical causes, such as thyroid problems or anemia. Treatment is effective. Psychotherapies with strong evidence include cognitive behavioural therapy, behavioural activation, interpersonal therapy, and mindfulness-based cognitive therapy for preventing relapse. Antidepressant medication can help, particularly for moderate to severe depression, and combining therapy and medication often works best. Regular sleep, physical activity, and social connection support recovery.

Getting Support at Pacific Maple Psych Centre

If you have been feeling low, empty, or not like yourself for weeks, therapy can help. Depression is treatable, and you do not have to wait until it gets worse to reach out.