Depression
 
Definition

Unipolar depressive disorder is a mood disorder state in which life experiences of loss, anger, sadness, or frustration outweigh a person's ability to effectively cope with daily experiences. To make a diagnosis of depression, five or more symptoms must be present without mania for last at least 2 weeks. Typically, the symptoms persist beyond 2 weeks. This particular mood disorder is very common and frequently undiagnosed, and involves emotional, cognitive, behavioural, and somatic disturbances. Depression is rated in terms of severity (mild, moderate, severe) and is classified by frequency (single episode, recurrent, or chronic [i.e., lasting more than 2 years]).

Psychodynamic influences (e.g., chronic stress, especially early childhood loss or deprivation), biologic factors (e.g., alteration of neurotransmitters including serotonin, acetylcholine, and catecholamines), and genetic predisposition (a recently identified gene called SERT that regulates serotonin, has been linked to depression) are all factors in the aetiology of depression. Other aspects contributing to this mood disorder include amount of light exposure, sleep disturbances, degree of social isolation, and nutritional deficiencies (e.g., of folate and omega-3 fatty acids). Many depressed patients report a precipitating stressful life event preceding their symptoms; the mood disorder can be immediate or delayed following a trauma such as loss of a loved one, abuse, or a natural disaster. Depression can also be precipitated by other medical conditions (e.g., myocardial infarction or cancer), as well as certain medications (e.g., antihypertensive, anticholesterolaemic, and antiarrhythmic agents).
 

Aetiology / Risk Factors

  • Prior episodes of depression, family history of depression, prior suicide gesture(s)
  • Female gender (lifetime risk, 20% to 25% for women and 7% to 12% for men); however, it has been suggested that men are more apt to mask depression with alcohol, raising the question of whether the incidence is actually greater in females, or whether women report the symptoms more frequently. Some reports indicate that in cultures/groups that abstain from alcohol use, the incidence of depression is equal in men and women.
  • Aged between 25 and 44—this is when the rate of occurrence is highest. The elderly are also at particular risk due to death of loved ones, physical illness, impaired function, and loss of independence.
  • Postpartum period
  • Medical or psychological comorbidity: e.g., autoimmune and other rheumatologic conditions, systemic cancers, coronary disease, thyroid disorders, chronic tension or migraine headaches, chronic pain, concurrent anxiety that also increases risk of suicide, obsessive-compulsive disorder, borderline personality disorder.
  • Stressful life events, especially loss (e.g., death of spouse, divorce, miscarriage), particularly loss at a young age (e.g., death of a parent or sibling),
  • History of abuse, lack of social support system
  • Current or past alcohol or drug abuse: 25% of those who abuse substances actually have depressive disorder.

Symptoms & Signs

  • Significantly depressed mood, anhedonia, and at least five of the following in the absence of a history of mania, current substance use/abuse (i.e., despite the frequency of concomitant depression, substances causing the affective symptoms must be ruled out), or normal grief reaction:
  • Insomnia (especially early morning awakening) or hypersomnia. Sleep disturbance is experienced by at least 90% of depressed patients; some data suggest that early treatment of sleep disorder prevents later development of depression,
  • Significant change in appetite and/or either weight loss or weight gain (appetite is generally not affected in dysthymia).
  • Fatigue and loss of energy
  • Feelings of worthlessness, self-reproach, inappropriate guilt
  • Extremely poor concentration
  • Either feelings of agitation, restlessness, and irritability or near complete inactivity and withdrawal
  • Recurrent thoughts of death or suicide
  • Feelings of hopelessness

Although the following symptoms are not generally considered to be defining characteristics, many depressed patients report:

  • Lack of libido (generally not with dysthymia)
  • Sudden bursts of anger—reported by up to 30% to 40%