What is Depression?

Causes of Depression

The exact cause of depression remains unclear, but it is generally understood to be the result of a complex interplay of biological, psychological, and environmental factors. For some people, depression may arise without any obvious cause, while for others, certain triggers or underlying factors may contribute to this mental condition. Some of the most commonly identified causes include:

1. Brain chemistry: An imbalance in neurotransmitters, the brain chemicals that regulate mood, thoughts, sleep, appetite and behaviour, may contribute to depression. These chemicals, such as serotonin, dopamine, and norepinephrine, play a key role in regulating mood, and disruptions in their functioning can lead to depressive symptoms.
2. Hormone levels: Changes in hormones, particularly during pregnancy, childbirth, or menopause, can increase the risk of depression. Conditions like thyroid disorders may also cause depression-like symptoms.
3. Childhood trauma: Adverse childhood experiences, such as abuse, neglect, or the loss of a loved one, can increase the likelihood of developing depression later in life.
4. Brain structure: Structural abnormalities in certain areas of the brain may play a role in depression. These changes could affect mood regulation and emotional processing.
5. Medical conditions: Chronic illnesses like diabetes, heart disease, or cancer can increase vulnerability to depression due to the physical and emotional toll they take on the body.
6. Substance use: A history of alcohol and drug misuse can contribute to or worsen depression by affecting brain function and mood.
7. Pain: chronic pain or ongoing physical discomfort can lead to depression, as the constant physical strain may cause emotional distress.

Risk factors of depression

Depression can affect anyone, but certain factors can increase your likelihood of developing the condition. These risk factors, which can be biological, psychological, or environmental, play a role in both the onset and severity of depression. Here are some common risk factors:

1. Sex (females): Depression is more commonly diagnosed in females than males. Hormonal fluctuations—such as those experienced during menstruation, pregnancy, and menopause—can increase the risk of depression in women. Additionally, women may be more likely to experience certain types of depression, such as postpartum depression.

2. Family history and genetics: A family history of depression or other mental health disorders can significantly increase the risk of developing depression.

3. Psychological and social factors: Stressful life events, such as the loss of a loved one, relationship issues, or financial difficulties, can trigger or exacerbate depression. Social isolation, lack of social support, and a history of abuse or neglect can also contribute to the development of depression.

4. Medical conditions: Chronic illnesses, such as heart disease, diabetes, cancer, or chronic pain conditions, increase the risk of depression. The physical toll of managing a long-term illness can lead to feelings of hopelessness or helplessness that may contribute to depression.

5. Inflammation: There is growing evidence linking inflammation in the body to the development of depression. Increased levels of inflammation are often observed in individuals with depression, suggesting that the inflammatory response of the immune system may impact brain function and mood regulation.

6. Traumatic brain injury (TBI): A history of traumatic brain injury can increase the risk of depression. Damage to certain areas of the brain may affect mood regulation and emotional responses, leading to depression.

7. Certain medications: Some medications, such as corticosteroids, certain blood pressure medications, and some hormonal birth control pills, may have side effects that contribute to depressive symptoms. If someone is on these medications, the risk of developing depression may be heightened.

8. Personality: People with certain personality traits, such as being overly self-critical, perfectionistic, or having low self-esteem, may be more susceptible to depression. A tendency to ruminate on negative thoughts can also increase the risk.

9. History of other mental health conditions: A previous diagnosis of other mental health conditions, such as anxiety or substance use disorders, can make a person more vulnerable to developing depression.

10. Lifestyle factors: Unhealthy lifestyle choices, such as lack of exercise, poor sleep habits, and high levels of stress, can increase the risk of depression.

11. Poor diet (vitamin D deficiency): Nutritional deficiencies, especially in vitamin D, have been linked to a higher risk of depression. Poor diet, including a lack of essential vitamins and minerals, can negatively affect brain function and mood regulation.

While having one or more of these risk factors does not guarantee someone will develop depression, they do contribute to an increased risk of this condition.

Key Facts of Depression

Major Symptoms	Persistent sadness, hopelessness, or emptiness Decreased pleasure or interest in activities once enjoyed Chronic tiredness, even after rest Difficulty concentrating, making decisions, or remembering things Significant weight loss or gain, overeating, or loss of appetite Insomnia or excessive sleeping Unexplained ache, pain, or digestive issues Feelings of guilt, worthlessness or self-blame Suicidal thoughts or attempts
Necessary Health Tests	Psychiatric evaluation Blood tests Imaging tests
Treatment	Medical therapy Psychotherapy Surgical and other interventions

Symptoms of Depression

Depression is a complex mental health condition that can look different for everyone, depending on things like age, gender, and personal circumstances. It can show up in various ways—from persistent sadness and fatigue to changes in appetite and sleep patterns. The problem is that many people do not realize they are dealing with depression because the signs are not always obvious. Getting to know the specific symptoms is the first step in recognising depression and taking steps to deal with the condition.

Common symptoms of depression

• Persistent sadness, hopelessness, or emptiness
• Decreased pleasure or interest in activities once enjoyed
• Chronic tiredness, even after rest
• Difficulty concentrating, making decisions, or remembering things
• Significant weight loss or gain, overeating, or loss of appetite
• Insomnia or excessive sleeping
• Unexplained ache, pain, or digestive issues
• Feelings of guilt, worthlessness or self-blame
• Suicidal thoughts or attempts

Symptoms in females

• Emotional highs and lows, heightened sensitivity
• Worsening symptoms during menstruation, pregnancy, or menopause
• Persistent exhaustion, even with sufficient rest
• Increased appetite or cravings, often for comfort foods
• Sleeping more than usual, difficulty waking up
• Increased feelings of anxiety or nervousness
• Heightened sense of guilt and self-blame
• Headaches, muscle pain, digestive issues
• Isolation from family, friends, or social activities

Symptoms in males

• Increased irritability or frustration, sometimes leading to anger
• Engaging in reckless actions, such as substance abuse or dangerous activities
• Trouble falling asleep or staying asleep
• Fatigue and tiredness, even without physical activities
• Lack of interest in hobbies, work, or relationships
• Avoiding emotional connection and interaction
• Less likely to express sadness or cry, instead showing frustration
• Unexplained physical pain, headache, digestive problems
• Higher likelihood of suicidal thoughts or attempts

Symptoms in children

• Excessive attachment to parents or caregivers, fear of being alone
• Increased irritability, frequent tantrums, or aggression
• Difficulty concentrating, decline in school performance
• Trouble falling asleep or nightmares
• Significant weight loss or gain, changes in eating habits
• Showing sadness or withdrawing from friends and family
• Overthinking, anxiety, or excessive concerns
• Lack of interest in usual activities or hobbies
• Frequent complaints of stomachaches, headaches, or other physical discomforts
• In older children or adolescents, thoughts of self-harm or suicide

Each of these symptoms can vary in intensity and may present differently depending on the age and gender of the person. If depression symptoms are noticed, seeking professional help is essential for proper diagnosis and care.

Types of depression

Based on the symptoms and severity of depression, it can be broken into these 5 main types:

1. Dysthymic disorder

Also known as persistent depressive disorder (PDD), dysthymia is characterized by chronic, low-grade depression lasting for at least two years. While the symptoms may not be as severe as major depression, they are long-lasting and can affect a person’s quality of life.

2. Unspecified depression

This term refers to cases where a person experiences depressive symptoms, but the exact cause or nature of the depression cannot be clearly identified. It may not meet the criteria for other types of depression but still causes significant distress.

3. Adjustment disorder with depression

This type of depression occurs in response to a specific stressor or life change, such as a breakup, job loss, or moving to a new location. The depressive symptoms appear within three months of the stressful event and can significantly impair daily functioning.

4. Bipolar depression

In bipolar disorder, depression occurs in cycles along with periods of mania or hypomania. During depressive episodes, individuals experience the typical symptoms of major depression, such as sadness, fatigue, and loss of interest in activities.

5. Seasonal affective disorder (SAD)

SAD is a type of depression that occurs seasonally, usually in the winter months when there is less natural sunlight. Symptoms often include fatigue, weight gain, and social withdrawal, improving during sunnier months.

Diagnosis of Depression

Diagnosing depression involves a combination of psychological evaluation, reviewing medical history, and sometimes additional tests to rule out other conditions.

1. Psychiatric evaluation

The primary way to diagnose depression is a comprehensive psychiatric evaluation. A healthcare provider, typically a psychiatrist or psychologist, conducts consultations to assess the symptoms of the patient, emotional state, and overall mental and physical functioning. The evaluation includes questions about mood, behaviour, and thoughts, as well as personal history and family background. To diagnose depression, the clinician typically relies on criteria from the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which lists specific symptoms and duration requirements. For instance, a diagnosis of major depressive disorder requires symptoms like persistent sadness, loss of interest, and fatigue lasting for at least two weeks.

2. Blood tests

Blood tests are often used to rule out other medical conditions that could be causing depressive symptoms. Conditions like hypothyroidism, vitamin D deficiency, or anemia can mimic depression and must be ruled out. Blood tests help ensure that depression is not secondary to another medical issue. In some cases, tests for hormonal imbalances may also be performed, particularly in women, as changes in hormone levels (e.g., thyroid or reproductive hormones) can contribute to depressive symptoms. The blood tests includes:

• Complete blood cell (CBC) count
• Thyroid-stimulating hormone (TSH)
• Vitamin B-12
• Rapid plasma reagin (RPR)
• HIV test
• Electrolytes, including calcium, phosphate, and magnesium levels
• Blood urea nitrogen (BUN) and creatinine
• Liver function tests (LFTs)
• Blood alcohol level
• Blood and urine toxicology screen

3. Imaging tests

In certain cases, especially when there is a concern about other neurological conditions, brain imaging tests like MRI or CT scans may be used. These tests can help rule out structural issues in the brain, such as tumors or injuries, that could be contributing to depressive symptoms. However, imaging tests are not typically part of the standard diagnostic process unless there are signs of neurological abnormalities.

Treatment of Depression

Depression can be effectively managed through a combination of medical therapy, psychotherapy, and, in some cases, surgical interventions. The goal of treatment is to reduce symptoms, improve quality of life, and prevent future episodes.

1. Medical therapy

Medication is a cornerstone of depression treatment. There are several classes of antidepressants, each working in different ways to alleviate symptoms:

• Typical antidepressants: Older classes of antidepressants include tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs). While effective, they are less commonly used today due to side effects and dietary restrictions (particularly MAOIs).
• Selective serotonin reuptake inhibitors (SSRIs): SSRIs, like fluoxetine (Prozac) and sertraline (Zoloft), are the most commonly prescribed antidepressants. They increase serotonin levels in the brain and are generally well-tolerated with fewer side effects than older medications.
• Serotonin and norepinephrine reuptake inhibitors (SNRIs): SNRIs, such as venlafaxine (Effexor) and duloxetine (Cymbalta), target both serotonin and norepinephrine. These can be particularly effective for individuals who do not respond to SSRIs.
• Monoamine oxidase inhibitors (MAOIs): MAOIs, such as phenelzine (Nardil), are potent antidepressants that block the enzyme monoamine oxidase, increasing levels of neurotransmitters like serotonin and dopamine. They are typically used when other antidepressants fail due to dietary restrictions and side effects.
• Tricyclic antidepressants (TCAs): TCAs, such as amitriptyline, are older drugs that are effective but often cause side effects like weight gain and dry mouth, making them less preferred today.

2. Psychotherapy

Psychotherapy plays a key role in managing depression, either alone or alongside medication. Common types of therapy include:

• Cognitive behavioural therapy (CBT): CBT helps individuals identify and change negative thought patterns and behaviours contributing to depression. It is one of the most widely used therapies for depression.
• Dialectical behaviuor therapy (DBT): DBT, a form of CBT, focuses on emotional regulation and interpersonal effectiveness. It is particularly helpful for individuals with mood instability or self-harm tendencies.
• Interpersonal therapy (IPT): IPT focuses on improving interpersonal relationships and addressing issues like grief, conflict, or role transitions that may contribute to depression.
• Light therapy: Especially effective for seasonal affective disorder (SAD), light therapy involves exposure to bright light to help regulate circadian rhythms and improve mood.
• Psychodynamic therapy: This therapy focuses on uncovering unconscious conflicts and past experiences that may be contributing to current depressive symptoms.
• Ketamine therapy: This is used to treat depression, anxiety, post-traumatic stress disorder (PTSD), end-of-life distress, chronic pain, drug/alcohol problems, and more.

3. Surgical and other interventions

For individuals with severe, treatment-resistant depression, more invasive treatments may be considered:

• Electroconvulsive therapy (ECT): ECT involves sending electrical impulses through the brain to induce controlled seizures. It is highly effective for severe depression, particularly when other treatments have not worked.
• Transcranial magnetic stimulation (TMS): TMS uses magnetic fields to stimulate nerve cells in the brain involved in mood regulation. It is a non-invasive procedure typically used for people with treatment-resistant depression.
• Vagus nerve stimulation (VNS): VNS involves implanting a device that sends electrical signals to the vagus nerve, which can help regulate mood. It is generally used for severe depression that has not responded to other treatments.

Remember, depression treatment is highly individualised. Combining medication, psychotherapy, and advanced interventions can lead to effective symptom management and improved quality of life for many individuals living with depression.