Depression

Depression is a very common, debilitating, life-threatening and often chronic medical disease. Research has shown that 15% of severely depressed people will ultimately commit suicide.

Depression is classified as a mood disorder

Mood disorders are defined by the presence of mood episodes (which can either be major depressive, manic, mixed, hypomanic mood episodes).These mood episodes represent a combination of symptoms comprising a predominant mood state.

Classification

Mood disorders are classified into the following:

• Depressive (major depressive disorder, dysthymia disorder)

• Bipolar (bipolar I/II disorder, cyclothymia disorder)

• Mood disorder secondary to general medical condition, substance abuse or medications.

DEPRESSIVE DISORDERS

Major Depressive Disorder (MDD) is diagnosed where there is a positive history of

one or more Major Depressive Episodes.

Epidemiology

The prevalence of MDD differs between males and females. The lifetime risk for a male is 2-4% compared to a female having a 5-9% lifetime risk. MDD has a mean age of onset of 30 years, compared to bipolar disorder which presents earlier, typically in adolescence.

Etiology of mood disorders are classified into different categories

Biological factors

• Biogenic amines, better known as neurotransmitters are mostly implicated in the etiology of mood disorders. Research has shown that noradrenaline and serotonin play a major role.
• Neuro-endocrine regulation with abnormalities in the limbic-hypothalamus-pituitary and adrenal axis together with abnormal sleeping patterns has been proven to play a role in the etiology of mood disorders.

Genetic factors

• Major depressive disorders and bipolar mood disorders run in families.

Psychosocial factors

• Life events and environmental stressors often precede the first episode of mood disorders e.g. the loss of a parent.
• Premorbid personality disorders such as obsessive-compulsive disorders, dependant personalities or histrionic personality traits.

 Risk factors

The following factors have been identified as risk factors for the development of MDD:

• Sex: female

• Age: onset in 25-50 age group

• Positive family history of depression and alcohol abuse

• Childhood experiences such as loss of a parent before 11 years old, negative home environment with abuse and neglect.

• Personality traits such as insecure, dependent, obsessional personality disorders

• Recent stressors

• Mothers who just delivered are at risk for developing MDD due to hormonal influences.

• Lack of intimate, confiding relationships (social isolation) 

Major depressive disorder is diagnosed when there is a positive history of one or more Major Depressive Episodes (MDE), in the absence of a previous manic, hypomanic, or mixed episode.

Major Depressive Episode can be diagnosed when:

A. at least five of the following symptoms have been present during the same two week period and represent a change from previous function, one of which must be either depressed mood or loss of interest:

• Depressed mood for most of the day, nearly every day, as indicated by either subjective report or observation made by others.
• Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day as indicated by either subjective account or observation of others.
• Significant weight loss when not dieting or weight gain, resulting in a change of more than five percent body weight in a month.
• Insomnia or hypersomnia nearly everyday.
• Psychomotor agitation or retardation, observed by others, or merely subjective feelings of restlessness or being slowed down.
• Fatigue or loss of energy nearly every day.
• Feelings of worthlessness or excessive or inappropriate guilt.
• Diminished ability to think or concentrate, or indecisiveness.
• Recurrent thoughts of death, recurrent suicidal ideation without a specific plan or a suicide attempt with a specific plan to commit suicide.

B. symptoms do not meet criteria for mixed episode as expected in bipolar mood type 2 disorder

C. symptoms cause significant social or occupational impairment/distress.

D. symptoms are not better explained due to physiological effects of a substance or due to a general medical condition.

E. symptoms not better accounted for by bereavement (a constellation of depressive symptoms meeting criteria for a MDE appearing within two months of the death of a close relative)

Treatment

The aim of treatment is complete remission, to treat the acute episode and prevent future episodes by continuing medication at full dose for 6-12months after remission.

This can be achieved by the following interventions:

• Biological: antidepressants, lithium, electroconvulsive therapy (ECT)

• Psychological: psychodynamic, cognitive, behavioural, family, and group therapy

• Social: vocational rehabilitation and social skills training

Antidepressants are classified into different classes

• SSRI (selective serotonin re-uptake inhibitors)
• TCA (tricyclic antidepressants)
• SNRI (serotonin and noradrenaline re-uptake inhibitors)
• NARI(noradrenaline re-uptake inhibitors)
• MAOI (monoamine oxidase inhibitors)

SSRIs are mostly used for the treatment of depression. They are all taken orally, are safe in overdose, better tolerated, have acceptability of long term use with a better side effect profile. Some of the most common side effects of the SSRIs include:

• Agitation, akathisia(restlessness), anxiety, panic attacks, insomnia, nausea, diarrhea,headache and sexual dysfunction

Available SSRIs include- fluoxetine,paroxetine, citalopram, escitalopram and sertraline.

Prognosis

The risk of recurrence is significant, with 50% relapse after the first episode, 75% after the second episode and 90% after the third episode.

Conclusion

Depression can be treated successfully with recovery being the rule, not the exception!