Depression is extremely common, with upto 30% of primary care patients having depressive symptoms. Depression may be the final expression of

• Genetic factors (neurotransmitter dysfunction)
• Developmental problems(personality problems, childhood events)
• Psychosocial stresses (divorce, unemployment)

It frequently presents in the form of somatic complaints with negative medical workups. Although sadness or grief are normal responses to loss, depression is not. Grief is usually accompanied by intact self-esteem, whereas depression is marked by a sense of guilt and worthlessness.

Major types of depressions:

1. Adjustment disorder with depressed mood

Depression may occur in reaction to some identifiable stressor or adverse life situation, usually loss of a person by death(grief reaction), divorce …, financial reversal (crisis) or loss of an established role such as being needed.

The disorder occurs within 3 months of the stressor and causes significant impairment in social or occupational functioning. The symptoms range from mild sadness, anxiety, irritability, worry, lack of concentration, discouragement and somatic complaints to the more severe symptoms.

2. Depressive disorders
   • Major depressive disorder:

A major depressive disorder consists of at least one episode of serious mood depression that occurs at any time of life. Complaints vary widely but mostly include a loss of interest and pleasure (anhedonia), withdrawal from activities, feelings of guilt.

Also  included are inability to concentrate some cognitive dysfunction, anxiety, chronic fatigue, feelings of worthlessness, somatic complaints, loss of sexual drive and thoughts of death. Vegetative signs that frequently occur are insomnia, anorexia with weight loss and constipation. Occasionally severe agitation and paranoia is present. These symptoms are common in depressed persons older than 50 years. Paranoid symptoms may range from general suspiciousness to ideas of reference with delusions. The somatic delusions frequently revolve around feelings of impending annihilation or hypochondrial beliefs (eg:- that the body is rotting with cancer), Hallucinations are uncommon.

Sub categories:

• Major depression with atypical features characterized by hypersomnia, over eating, lethargy, rejection sensitivity…
• Major depression with seasonal onset (seasonal affective disorder) is a dysfunction of circadin rhythms that occurs more commonly in the winter months and is believed to be due to the decreased exposure to full spectrum light. Common symptoms include carbohydrate craving, lethargy, hyperphagia and hypersomnia
• Major depression with postpartum onset usually occurs 2 weeks to 6 weeks postpartum(birth of a child). Most women (upto 80%) experience some mild letdown of mood in the postpartum period. For some of these (10-15%), the symptoms are more severe and similar to those usually seen in serious depression, with an increased emphasis on concerns related to the baby (obsessive thoughts about harming it or inability to care for it). When psychotic symptoms occur, there is frequently  associated sleep deprivation, volatility of behaviour and manic like symptoms. Postpartum psychosis is much less common(<2%), often occurs within the first 2 weeks, requires early and aggressive management. Biologic vulnerability with hormonol changes psychosocial stressors all play a role.

The chances of second episode are about 25% and may be reduced with prophylactic treatment.

• Dysthymia

Dysthymia is  a chronic depressive disturbance. Sadness. loss of interest, and withdrawal of activities over a period of 2 or more years with a relatively persistent course is necessary for this diagnosis.  Generally the symptoms are milder but longer lasting than those in major depressive phase.

• Premenstrual dysphoric disorder

Depressive symptoms during the late luteal phase of the menstrual cycles may occur throughout the year.

3. Biploar disorders

Bipolar disorders consist of episodic mood shifts into mania, major depression ,hypomania, and mixed mood states. The ability of bipolar disorder to mimic aspects of many other Axis I disorders and a high comorbidity with substance abuse can make the initial diagnosis of bipolar disorder difficult.

• Mania: A manic episode is a mood change characterized by elation with hyperactivity, over involvement in life activities, increased irritability, flight of ideas, easy distractibility and little need of sleep.

The over enthusiastic quality of the mood  and the expansive behaviour initially attracts others, but the irritability, mood liability with swings into depression, aggressive behaviour and grandiosity usually lead to marked interpersonal difficulties. Activities may occur that are later regretted eg; excessive spending, resignation from a job, a hasty marriage, sexual acting out, and exhibitionist behaviour with alienation of friends and family. A typical manic episodes can include gross delusions, paranoid ideation of severe proportions and auditory hallucinations usually related to some grandiose perception.

The episodes begin abruptly (sometime precipitated by life stresses) and may last from several days to months. Spring and summer tend to be peak periods.

Manic patients differ from patients with schizophrenia in that the former use more effective interpersonal manoeuvres and are mote sensitive to the social manoeuvres of others, and are able to utilize weakness and vulnerability in others to their own advantage.

• Cyclothymic disorders: These are chronic mood disturbances with episodes of depression and hypomania. The symptoms must have at least a 2year duration and are milder than those that occur in depressive or manic episodes. Occasionally, the symptoms will escalate into a full-blown manic or depressive episode, in which case reclassification as Bipolar I or Bipolar II disorder would be warranted.

4. Mood disorders secondary to illness and drugs

Any illness severe or mild can cause significant depression. Conditions such as rheumatoid arthiritis, multiple sclerosis and chronic heart diseases are particularly likely to be associated with depression as are other chronic illnesses. Hormonal variations clearly play a role in some depressions. Varying degrees of depression occur at various times in schizophrenic disorders central nervous system disease and organic mental states. Alcohol dependency frequently coexists with serious depression.

References

“Current Medical Diagnosis & Treatment”, 45th edition