Depression (Mood)

Depression is a state of low mood and aversion to activity that affects more than 280 million people worldwide, impacting thoughts, behaviour, feelings, and overall well-being. It can result in loss of interest in activities, reduced pleasure, and significant functional impairment.

Depression is associated with various contributing factors, including life events, personality traits, medical conditions, and side effects of medical treatments.

Signs and Symptoms

Depression presents with a range of symptoms including persistent low mood, aversion to activity, loss of interest or pleasure in previously enjoyable activities, and significant changes in appetite and sleep patterns. Cognitive symptoms include difficulty in thinking, concentrating, and making decisions.

Affected individuals may experience feelings of worthlessness, excessive guilt, and recurrent thoughts of death or suicide. Physical symptoms can include fatigue, changes in weight, and unexplained aches and pains.

Contributing Factors

Life Events

Adverse childhood experiences such as abuse, neglect, and bereavement significantly increase the risk of depression in adulthood. Major life changes, including childbirth, menopause, financial difficulties, unemployment, and chronic stress, are also common triggers.

Adolescents are particularly vulnerable to depression following social rejection, peer pressure, or bullying.

Personality

Individuals with high levels of neuroticism and low extraversion are more susceptible to depression. Low conscientiousness, associated with disorganisation and dissatisfaction, further increases the risk.

Medical Treatments and Substances

Certain medications, such as early-generation beta-blockers, alpha interferon therapy, finasteride, and isotretinoin, have been linked to depression. Substance abuse, including alcohol, sedatives, opioids, stimulants, and hallucinogens, can also cause or exacerbate depressive symptoms.

Non-psychiatric Illnesses

Depression can result from various medical conditions, including hormonal imbalances (hypothyroidism, hypoandrogenism), chronic pain, neurological disorders (Parkinson's disease, multiple sclerosis), and infections (HIV, Lyme disease). Chronic pain is notably associated with high rates of depression, affecting up to 85% of patients.

Diagnosis

Depression is diagnosed using standardised questionnaires such as the Patient Health Questionnaire (PHQ-9) and the Beck Depression Inventory. These tools assess the severity of depressive symptoms and help guide treatment decisions.

Management

Psychotherapy and Psychopharmacology

Treatment typically involves psychotherapy, such as cognitive-behavioural therapy (CBT), and psychopharmacology, including antidepressants like selective serotonin reuptake inhibitors (SSRIs). Antidepressants are not recommended for mild depression due to a poor risk-benefit ratio, but they may be beneficial for moderate to severe cases.

Lifestyle Interventions

Regular physical activity has a protective effect against depression. Yoga and reminiscence therapy are additional approaches that may benefit certain individuals.

Social connections and maintaining a supportive network are very important preventive measures.

Epidemiology

Depression is the leading cause of disability worldwide, affecting 4.4% of the global population. It is more prevalent in women, young people, and the elderly.

Barriers to treatment in low- and middle-income countries include inaccurate assessment, lack of trained healthcare providers, social stigma, and resource limitations. Unemployment and competitive environments are significant risk factors for developing depression.

The World Health Organisation's Mental Health Gap Action Programme (mhGAP) aims to increase services for people with mental disorders, including depression, especially in low-resource settings. Effective screening and early intervention are very important for improving outcomes.

Depression has been recognised historically as a significant mental health condition, with evolving theories and treatments reflecting advances in medical and psychological understanding. Modern treatments focus on a combination of therapeutic approaches and lifestyle modifications to manage symptoms and improve quality of life for those affected.

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Self-assessment MCQs (single best answer)

Which of the following is NOT a common symptom of depression?

Which personality trait is most associated with a higher risk of depression?

Which medication is linked to an increased risk of depression as a side effect?

Which screening tool is commonly used to assess the severity of depression?

Which of the following is a risk factor for depression in adolescents?

Which medical condition is NOT typically associated with an increased risk of depression?

What is the main focus of cognitive-behavioural therapy (CBT) in treating depression?

Which factor is least likely to contribute to the development of depression?

Which neurotransmitter imbalance was historically thought to be a primary cause of depression?

What is the primary goal of the World Health Organisation's Mental Health Gap Action Programme (mhGAP) concerning depression?