seasonal affective disorder (redirected from Seasonal depression)

Seasonal Affective Disorder 

Definition

Seasonal affective disorder (SAD) is a form of depression most often associated with the lack of daylight in extreme northern and southern latitudes from the late fall to the early spring.

Description

Although researchers are not certain what causes seasonal affective disorder, they suspect that it has something to do with the hormone melatonin. Melatonin is thought to play an active role in regulating the "internal body clock," which dictates when humans feel like going to bed at night and getting up in the morning. Although seasonal affective disorder is most common when light is low, it may occur in the spring, and it is then often called reverse SAD.

Causes and symptoms

The body produces more melatonin at night than during the day, and scientists believe it helps people feel sleepy at nighttime. There is also more melatonin in the body during winter, when the days are shorter. Some researchers believe that excessive melatonin release during winter in people with SAD may account for their feelings of drowsiness or depression. One variation on this idea is that, during winter, people's internal clocks may become out of sync with the light-dark cycle, leading to a long-term disruption in melatonin release.

Seasonal affective disorder, while not an official category of mental illness listed by the American Psychiatric Association, is estimated to affect 10 million Americans, most of whom are women. Another 25 million Americans may have a mild form of SAD, sometimes called the "winter blues" or "winter blahs." The risk of SAD increases the further from the equator a person lives.

The symptoms of SAD are similar to those of other forms of depression. People with SAD may feel sad, irritable, or tired, and may find themselves sleeping too much. They may also lose interest in normal or pleasurable activities (including sex), become withdrawn, crave carbohydrates, and gain weight.

Diagnosis

Doctors usually diagnose seasonal affective disorder based on the patient's description of symptoms, including the time of year they occur.

Treatment

The first-line treatment for seasonal affective disorder is light therapy, exposing the patient to bright artificial light to compensate for the gloominess of winter. Light therapy uses a device called a light box, which contains a set of fluorescent or incandescent lights in front of a reflector. Typically, the patient sits for 30 minutes next to a 10,000-lux box (which is about 50 times as bright as ordinary indoor light). Light therapy appears to be safe for most people. However, it may be harmful for those with eye diseases. The most common side effects are vision problems such as eye strain, headaches, irritability, and insomnia. In addition, hypomania (elevated or expansive mood, characterized by hyperactivity and inflated self esteem) may occasionally occur.

Recently, researchers have begun testing whether people who do not completely respond to light therapy can benefit from tiny doses of the hormone melatonin to reset the body's internal clock. Early results look promising, but the potential benefits must be confirmed in larger studies before this type of treatment becomes widely accepted.

Like other types of mood disorders, seasonal affective disorder may also respond to medication and psychotherapy. The four different classes of drugs used for mood disorders are:

• heterocyclic antidepressants (HCAs), such as amitriptyline (Elavil)
• selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine (Prozac), paroxetine (Paxil), and sertraline (Zoloft)
• monoamine oxidase inhibitors (MAO inhibitors), such as phenelzine sulfate (Nardil) and tranylcypromine sulfate (Parnate)
• Lithium salts, such as lithium carbonate (Eskalith), often used in people with bipolar mood disorders, are often useful with SAD patients; many SAD patients also suffer from bipolar disorder (excessive mood swings; formerly known as manic depression)

A number of psychotherapy approaches are useful as well. Interpersonal psychotherapy helps patients recognize how their mood disorder and their interpersonal relationships interact. Cognitive-behavioral therapy explores how the patient's view of the world may be affecting mood and outlook.

Prognosis

Most patients with seasonal affective disorder respond to light therapy and/or antidepressant drugs.

Resources

Organizations

American Psychiatric Association. 1400 K Street NW, Washington DC 20005. (888) 357-7924. http://www.psych.org.

National Depressive and Manic Depressive Association (NDMDA). 730 N. Franklin St., Ste. 501, Chicago, IL 60610. (800) 826-3632. http://www.ndmda.org.

National Institute of Mental Health. Mental Health Public Inquiries, 5600 Fishers Lane, Room 15C-05, Rockville, MD 20857. (888) 826-9438. http://www.nimh.nih.gov.

Key terms

Cognitive behavioral therapy — Psychotherapy aimed at helping people change their attitudes, perceptions, and patterns of thinking.

Melatonin — A naturally occurring hormone involved in regulating the body's "internal clock."

Serotonin — A chemical messenger in the brain thought to play a role in regulating mood.

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disorder /dis·or·der/ (dis-or´der) a derangement or abnormality of function; a morbid physical or mental state.

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acute stress disorder  an anxiety disorder characterized by development of anxiety, dissociative, and other symptoms within one month following exposure to an extremely traumatic event. If persistent, it may become posttraumatic stress disorder.

adjustment disorder  maladaptive reaction to identifiable stress (e.g., divorce, illness), which is assumed to remit when the stress ceases or when the patient adapts.

affective disorders  mood d's.

amnestic disorders  mental disorders characterized by acquired impairment in the ability to learn and recall new information, sometimes accompanied by inability to recall previously learned information.

anxiety disorders  mental disorders in which anxiety and avoidance behavior predominate, i.e., panic disorder, agoraphobia, social phobia, specific phobia, obsessive-compulsive disorder, posttraumatic stress disorder, acute stress disorder, generalized anxiety disorder, and substance-induced anxiety disorder.

attention-deficit/hyperactivity disorder  a controversial childhood mental disorder with onset before age seven, and characterized by inattention (e.g., distractibility, forgetfulness, not appearing to listen), by hyperactivity and impulsivity (e.g., restlessness, excessive running or climbing, excessive talking, and other disruptive behavior), or by a combination of both types of behavior.

autistic disorder  autism; a severe pervasive developmental disorder with onset usually before three years of age and a biological basis; it is characterized by qualitative impairment in reciprocal social interaction, verbal and nonverbal communication, and capacity for symbolic play, by restricted and unusual repertoire of activities and interests, and often by cognitive impairment.

behavior disorder  conduct d.

binge-eating disorder  an eating disorder characterized by repeated episodes of binge eating, as in bulimia nervosa, but not followed by inappropriate compensatory behavior such as purging, fasting, or excessive exercise.

bipolar disorders  mood disorders with a history of manic, mixed, or hypomanic episodes, usually with present or previous history of one or more major depressive episodes; included are bipolar I d., characterized by one or more manic or mixed episodes, bipolar II d., characterized by one or more hypomanic episodes but no manic episodes, and cyclothymic disorder. The term is sometimes used in the singular to denote either bipolar I disorder, bipolar II disorder, or both.

body dysmorphic disorder  a somatoform disorder characterized by a normal-looking person's preoccupation with an imagined defect in appearance.

breathing-related sleep disorder  any of several disorders characterized by sleep disruption due to some sleep-related breathing problem, resulting in excessive sleepiness or insomnia.

brief psychotic disorder  an episode of psychotic symptoms with sudden onset, lasting less than one month.

catatonic disorder  catatonia due to the physiological effects of a general medical condition and neither better accounted for by another mental disorder nor occurring exclusively during delirium.

character disorders  personality d's.

childhood disintegrative disorder  pervasive developmental disorder characterized by marked regression in various developmental skills, including language, play, and social and motor skills, after two to ten years of initial normal development.

circadian rhythm sleep disorder  a lack of synchrony between the schedule of sleeping and waking required by the external environment and that of a person's own circadian rhythm.

collagen disorder  an inborn error of metabolism involving abnormal structure or metabolism of collagen, e.g., Marfan syndrome, cutis laxa. Cf. collagen disease.

communication disorders  mental disorders characterized by difficulties with speech or language, severe enough to interfere academically, occupationally, or socially.

conduct disorder  a type of disruptive behavior disorder of childhood and adolescence marked by persistent violation of the rights of others or of age-appropriate societal norms or rules.

conversion disorder  a somatoform disorder characterized by conversion symptoms (loss or alteration of voluntary motor or sensory functioning suggesting physical illness) with no physiological basis and not produced intentionally or feigned; a psychological basis is suggested by exacerbation of symptoms during psychological stress, relief from tension (primary gain), or gain of outside support or attention (secondary gains).

cyclothymic disorder  a mood disorder characterized by alternating cycles of hypomanic and depressive periods with symptoms like those of manic and major depressive episodes but of lesser severity.

delusional disorder  a mental disorder marked by well-organized, logically consistent delusions of grandeur, persecution, or jealousy, with no other psychotic feature. There are six types: persecutory, jealous, erotomanic, somatic, grandiose, and mixed.

depersonalization disorder  a dissociative disorder characterized by intense, prolonged, or otherwise troubling feelings of detachment from one's body or thoughts, not secondary to another mental disorder.

depressive disorders  mood disorders in which depression is unaccompanied by manic or hypomanic episodes.

developmental coordination disorder  problematic or delayed development of gross and fine motor coordination skills, not due to a neurological disorder or to general mental retardation, resulting in the appearance of clumsiness.

disruptive behavior disorders  a group of mental disorders of children and adolescents consisting of behavior that violates social norms and is disruptive.

dissociative disorders  mental disorders characterized by sudden, temporary alterations in identity, memory, or consciousness, segregating normally integrated parts of one's personality from one's dominant identity.

dissociative identity disorder  a dissociative disorder characterized by the existence in an individual of two or more distinct personalities, with at least two of the personalities controlling the patient's behavior in turns. The host personality usually is totally unaware of the alternate personalities; alternate personalities may or may not have awareness of the others.

dream anxiety disorder  nightmare d.

dysthymic disorder  a mood disorder characterized by depressed feeling, loss of interest or pleasure in one's usual activities, and other symptoms typical of depression but tending to be longer in duration and less severe than in major depressive disorder.

eating disorder  abnormal feeding habits associated with psychological factors, including anorexia nervosa, bulimia nervosa, pica, and rumination disorder.

expressive language disorder  a communication disorder occurring in children and characterized by problems with the expression of language, either oral or signed.

factitious disorder  a mental disorder characterized by repeated, intentional simulation of physical or psychological signs and symptoms of illness for no apparent purpose other than obtaining treatment.

factitious disorder by proxy  a form of factitious disorder in which one person (usually a mother) intentionally fabricates or induces physical (Munchausen syndrome by proxy) or psychological disorders in another person under their care (usually their child) and subjects that person to needless diagnostic procedures or treatment, without any external incentives for the behavior.

female orgasmic disorder  consistently delayed or absent orgasm in a female, even after a normal phase of sexual excitement and adequate stimulation.

female sexual arousal disorder  a sexual dysfunction involving failure by a female either to attain or maintain lubrication and swelling during sexual activity, after adequate stimulation.

functional disorder  a disorder of physiological function having no known organic basis.

gender identity disorder  a disturbance of gender identification in which the affected person has an overwhelming desire to change their anatomic sex or insists that they are of the opposite sex, with persistent discomfort about their assigned sex or about filling its usual gender role.

generalized anxiety disorder  (GAD) an anxiety disorder characterized by excessive, uncontrollable worry about two or more life circumstances for six months or more.

hypoactive sexual desire disorder  a sexual dysfunction consisting of persistently or recurrently low level or absence of sexual fantasies and desire for sexual activity.

impulse control disorders  a group of mental disorders characterized by repeated failure to resist an impulse to perform some act harmful to oneself or to others.

induced psychotic disorder  shared psychotic d.

intermittent explosive disorder  an impulse control disorder characterized by multiple discrete episodes of loss of control of aggressive impulses resulting in serious assault or destruction of property that are out of proportion to any precipitating stressors.

learning disorders  a group of disorders characterized by academic functioning that is substantially below the level expected on the basis of the patient's age, intelligence, and education.

lymphoproliferative disorders  a group of malignant neoplasms arising from cells related to the common multipotential lymphoreticular cell, including lymphocytic, histiocytic, and monocytic leukemias, multiple myeloma, plasmacytoma, and Hodgkin's disease.

lymphoreticular disorders  a group of disorders of the lymphoreticular system, characterized by the proliferation of lymphocytes or lymphoid tissues.

major depressive disorder  a mood disorder characterized by the occurrence of one or more major depressive episodes and the absence of any history of manic, mixed, or hypomanic episodes.

male erectile disorder  a sexual dysfunction involving failure by a male to attain or maintain an adequate erection until completion of sexual relations.

male orgasmic disorder  consistently delayed or absent orgasm in a male, even after a normal phase of sexual excitement and stimulation adequate for his age.

manic-depressive disorder  former name for a mood disorder now known as bipolar I d. or bipolar II d. and often called bipolar d. (q.v.).

mendelian disorder  a genetic disease showing a mendelian pattern of inheritance, caused by a single mutation in the structure of DNA, which causes a single basic defect with pathologic consequences.

mental disorder  any clinically significant behavioral or psychological syndrome characterized by the presence of distressing symptoms, impairment of functioning, or significantly increased risk of suffering death, pain, or other disability.

minor depressive disorder  a mood disorder closely resembling major depressive disorder and dysthymic disorder but intermediate in severity between the two.

mixed receptive-expressive language disorder  a communication disorder involving both the expression and the comprehension of language, either spoken or signed.

monogenic disorder  mendelian d.

mood disorders  mental disorders characterized by disturbances of mood manifested as one or more episodes of mania, hypomania, depression, or some combination, the two main subcategories being bipolar disorders and depressive disorders.

motor skills disorder  any disorder characterized by inadequate development of motor coordination severe enough to restrict locomotion or the ability to perform tasks, schoolwork, or other activities.

multifactorial disorder  one caused by the interaction of genetic and sometimes also nongenetic, environmental factors, e.g., diabetes mellitus.

multiple personality disorder  dissociative identity d.

myeloproliferative disorders  a group of usually neoplastic diseases possibly related histogenetically, including granulocytic leukemias, myelomonocytic leukemias, polycythemia vera, and myelofibroerythroleukemia.

neurotic disorder  neurosis.

nightmare disorder  repeated episodes of nightmares that awaken the sleeper, with full orientation and alertness and vivid recall of the dreams.

obsessive-compulsive disorder  (OCD) an anxiety disorder characterized by recurrent obsessions or compulsions, which are severe enough to interfere significantly with personal or social functioning. Cf. obsessive-compulsive personality disorder, under personality .

obsessive-compulsive personality disorder  see under personality.

oppositional defiant disorder  a type of disruptive behavior disorder characterized by a recurrent pattern of defiant, hostile, disobedient, and negativistic behavior directed toward those in authority.

organic mental disorder  a term formerly used to denote any mental disorder with a specifically known or presumed organic etiology. It was sometimes used synonymously with organic mental syndrome.

orgasmic disorders  sexual dysfunctions characterized by inhibited or premature orgasm; see female orgasmic d., male orgasmic d., and premature ejaculation.

pain disorder  a somatoform disorder characterized by a chief complaint of severe chronic pain which is neither feigned nor intentionally produced, but in which psychological factors appear to play a major role in onset, severity, exacerbation, or maintenance.

panic disorder  an anxiety disorder characterized by attacks of panic (anxiety), fear, or terror, by feelings of unreality, or by fears of dying, or losing control, together with somatic signs such as dyspnea, choking, palpitations, dizziness, vertigo, flushing or pallor, and sweating. It may occur with or, rarely, without agoraphobia.

paranoid disorder  older term for delusional d.

personality disorders  a category of mental disorders characterized by enduring, inflexible, and maladaptive personality traits that deviate markedly from cultural expectations and either generate subjective distress or significantly impair functioning. For specific disorders, see under personality.

pervasive developmental disorders  disorders in which there is impaired development in multiple areas, including reciprocal social interactions, verbal and nonverbal communications, and imaginative activity, as in autistic disorder.

phagocytic dysfunction disorders  a group of immunodeficiency conditions characterized by disordered phagocytic activity, occurring as both extrinsic and intrinsic types. Bacterial or fungal infections may range from mild skin infection to fatal systemic infection.

phobic disorders  see phobia.

phonological disorder  a communication disorder characterized by failure to use age- and dialect-appropriate sounds in speaking, with errors occurring in the selection, production, or articulation of sounds.

plasma cell disorders  see under dyscrasia.

postconcussional disorder  see under syndrome.

posttraumatic stress disorder  (PTSD) an anxiety disorder caused by an intensely traumatic event, characterized by mentally reexperiencing the trauma, avoidance of trauma-associated stimuli, numbing of emotional responsiveness, and hyperalertness and difficulty in sleeping, remembering, or concentrating.

premenstrual dysphoric disorder  premenstrual syndrome viewed as a psychiatric disorder.

psychoactive substance use disorders  substance use d's.

psychosomatic disorder  one in which the physical symptoms are caused or exacerbated by psychological factors, as in migraine headaches, lower back pain, or irritable bowel syndrome.

psychotic disorder  psychosis.

reactive attachment disorder  a mental disorder of infancy or early childhood characterized by notably unusual and developmentally inappropriate social relatedness, usually associated with grossly pathological care.

rumination disorder  excessive rumination of food by infants, after a period of normal eating habits, potentially leading to death by malnutrition.

schizoaffective disorder  a mental disorder in which symptoms of a mood disorder occur along with prominent psychotic symptoms characteristic of schizophrenia.

schizophreniform disorder  a mental disorder with the signs and symptoms of schizophrenia but of less than six months' duration.

seasonal affective disorder  (SAD) depression with fatigue, lethargy, oversleeping, overeating, and carbohydrate craving recurring cyclically during specific seasons, most commonly the winter months.

separation anxiety disorder  prolonged, developmentally inappropriate, excessive anxiety and distress in a child concerning removal from parents, home, or familiar surroundings.

sexual disorders 

1. any disorders involving sexual functioning, desire, or performance.

2. specifically, any such disorder that is caused at least in part by psychological factors; divided into sexual dysfunctions and paraphilias.

sexual arousal disorders  sexual dysfunctions characterized by alterations in sexual arousal; see female sexual arousal d. and male erectile d.

sexual aversion disorder  feelings of repugnance for and active avoidance of genital sexual contact with a partner, causing substantial distress or interpersonal difficulty.

sexual desire disorders  sexual dysfunctions characterized by alteration in sexual desire; see hypoactive sexual desire d. and sexual aversion d.

sexual pain disorders  sexual dysfunctions characterized by pain associated with intercourse; it includes dyspareunia and vaginismus not due to a general medical condition.

shared psychotic disorder  a delusional system that develops in one or more persons as a result of a close relationship with someone who already has a psychotic disorder with prominent delusions.

sleep disorders  chronic disorders involving sleep, either primary (dyssomnias, parasomnias) or secondary to factors including a general medical condition, mental disorder, or substance use.

sleep terror disorder  a sleep disorder of repeated episodes of pavor nocturnus.

sleepwalking disorder  a sleep disorder of the parasomnia group, consisting of repeated episodes of somnambulism.

social anxiety disorder  social phobia.

somatization disorder  a somatoform disorder characterized by multiple somatic complaints, including a combination of pain, gastrointestinal, sexual, and neurological symptoms, and not fully explainable by any known general medical condition or the direct effect of a substance, but not intentionally feigned or produced.

somatoform disorders  mental disorders characterized by symptoms suggesting physical disorders of psychogenic origin but not under voluntary control, e.g., body dysmorphic disorder, conversion disorder, hypochondriasis, pain disorder, somatization disorder, and undifferentiated somatoform disorder.

somatoform pain disorder  pain d.

speech disorder  defective ability to speak; it may be either psychogenic (see communication d. ) or neurogenic. See also aphasia, aphonia, dysphasia, and dysphonia.

stereotypic movement disorder  a mental disorder characterized by repetitive nonfunctional motor behavior that often appears to be driven and can result in serious self-inflicted injuries.

substance-induced disorders  a subgroup of the substance-related disorders comprising a variety of behavioral or psychological anomalies resulting from ingestion of or exposure to a drug of abuse, medication, or toxin. Cf. substance use d's.

substance-related disorders  any of the mental disorders associated with excessive use of or exposure to psychoactive substances, including drugs of abuse, medications, and toxins. The group is divided into substance use d's and substance-induced d's .

substance use disorders  a subgroup of the substance-related disorders, in which psychoactive substance use or abuse repeatedly results in significantly adverse consequences. The group comprises substance abuse and substance dependence.

undifferentiated somatoform disorder  one or more physical complaints, not intentionally produced or feigned and persisting for at least six months, that cannot be fully explained by a general medical condition or the direct effects of a substance.

unipolar disorders  depressive d's.

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sea·son·al affective disorder (sz-nl)

n. Abbr. SAD

A mood disorder occurring during seasons when sunlight is limited, characterized by symptoms of depression.

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seasonal affective disorder (SAD)

[sē′zənəl]

a DSM-IV mood disorder associated with the shorter days and longer nights of autumn and winter. Symptoms include lethargy, depression, social withdrawal, and work difficulties. The patients also consume excess amounts of carbohydrates, gaining weight. The symptoms recede in the spring, when days become longer. The condition is associated with the effect of light on melatonin secretion and is treated with light therapy for 5 to 6 hours per day.

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seasonal affective disorder (SAD),

n a mood disorder associated with the shorter days and longer nights of autumn and winter. Symptoms include lethargy, depression, social withdrawal, and work difficulties.

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seasonal affective disorder

SAD, winter 'blues,' winter depression Psychiatry A clinical form of depression with an onset in late fall and remission in spring. See Bright light therapy; Cf Melancholia, Melanocholy.