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Recurrent Major Depressive Disorder With a Seasonal Pattern


Key Points

  • Recurrent major depressive disorder with a seasonal pattern is diagnosed in patients when symptoms of depression emerge at a particular time of year, usually in winter
  • Diagnosis is based on the recognition of major depressive episodes occurring at a specific time of the year, causing social or occupational impairment, with the presence of at least 5 of the following symptoms, necessarily including depressed/irritable mood or anhedonia:
    • Depressed mood or irritability for most of the day, and nearly every day, indicated via subjective report of the patient or via observation of others
    • Anhedonia
    • Sleep disturbance
    • Change in weight or appetite
    • Psychomotor retardation or agitation
    • Fatigue or loss of energy
    • Feelings of worthlessness or excessive or inappropriate guilt
    • Diminished ability to concentrate or indecisiveness
    • Recurrent thoughts of death, suicidal ideation, suicide attempt, or a specific plan for committing suicide
  • Must be differentiated from hypothyroidism, major depressive disorder, bipolar disorders I and II, cyclothymic disorder, and substance abuse
  • Principal treatment modalities consist of light therapy, cognitive behavioral therapy, and selective serotonin reuptake inhibitors
    • Of these treatment options, evidence of efficacy is strongest for light therapy and cognitive behavioral therapy, which can be used in concert as well as individually
    • In the case of fall/winter seasonality, light therapy is useful not only for treatment, but also as a prevention modality if begun in early fall

Urgent Action

  • Recognition of suicidal or homicidal ideation is urgent; when present, this warrants immediate referral to a psychiatrist and admission to psychiatric unit


  • Failure to recognize the seasonality element of the condition can result in misdiagnosis (eg, cyclothymic disorder), leading to failure to implement effective treatment
  • Failure to recognize a patient’s suicidal or homicidal risk can lead to tragic consequences of an otherwise manageable condition


Clinical Clarification

  • Recurrent major depressive disorder with a seasonal pattern is a major depressive disorder with a regular temporal relationship between symptomatic episodes and a particular time of the year r1


  • DSM-5 considers seasonality as an episode specifier for recurrent major depressive disorder r2
    • Symptoms must be present most days, throughout most of the day, during the same 2-week period and must include at least 1 of the following:
      • Depressed mood or irritability nearly every day, indicated via subjective report of the patient or via observation made by others
      • Anhedonia
    • In addition to 4 of the following:
      • Sleep disturbance
      • Change in weight or appetite
      • Change in usual amount of activity (psychomotor retardation or agitation), as reported by patient or observed by others
      • Fatigue or loss of energy
      • Feelings of worthlessness or excessive or inappropriate guilt
      • Diminished ability to concentrate or indecisiveness
      • Recurrent thoughts of death, suicidal ideation, suicide attempt, or a specific plan for committing suicide
    • Mnemonic device SIG E CAPS can be helpful to remember symptoms other than moodr3:
      • Sleep changes
      • Decreased Interest (anhedonia)
      • Increased feelings of Guilt
      • Decreased Energy
      • Impaired Concentration
      • Appetite changes
      • Psychomotor changes
      • Suicidal thoughts or actions
    • Symptoms are associated with impaired social or occupational function, and cannot be attributed to physiologic effects of a substance or medical disorder
    • Depressive episodes must occur during a particular time of the year with predictable annual recurrence r1
    • 2 depressive episodes must have occurred in the previous 2 years, without patient having experienced any nonseasonal depressive episodes during that period
  • Recurrent major depressive disorder with a seasonal pattern can be further classified into 2 subtypes, based on the time of year in which episodes occur r1
    • Winter or fall/winter recurrence
      • Accounts for the vast majority of cases, especially in populations living at high latitudes
      • Certain ethnic groups who live at very high latitudes and their descendants may have adapted to long winters and therefore are less prone
    • Summer or spring/summer recurrence
      • Constitutes only the minority of cases (0.1%) r1r4
  • A subsyndromal type of seasonal depression, manifesting mostly with sleep disturbances, has been reported among individuals staying at Arctic and Antarctic sites r5


Clinical Presentation


  • Seasonal pattern of symptoms
  • Any of the following symptoms or complaints are common:
    • Decline in performance at work or school c1c2
    • Change in sleep, appetite, or weight (gaining or losing more than 5% body weight within a month, as reported by patient or observed by others) r2c3c4c5
      • Hypersomnia with hyperphagia and weight gain is typical of recurrent major depressive disorder with fall/winter seasonal pattern, as if patient were in a quasi-hibernation state c6c7c8c9c10c11
      • Opposite symptom profile is typical of spring/summer pattern (ie, patient sleeps less, eats less, loses weight) c12c13c14c15c16c17
    • Fatigue c18
    • Loss of interest in sexual activity c19
    • Headache or other pain c20
    • Concentration difficulty, indecisiveness, or memory impairment c21c22c23
    • Nausea c24
    • Change in bowel habits (constipation or diarrhea) c25c26c27
    • Craving for carbohydrates c28
    • Difficulty with morning awakening c29
  • Additional symptoms that may be present include:
    • Anxiety or worry c30c31
    • Suicidal ideation or thoughts of death c32
    • Feelings of guilt or worthlessness c33c34
    • Preoccupation with physical discomfort c35
    • Symptoms of psychosis (eg, delusions, hallucinations) c36c37c38

Physical examination

  • Physical findings can include:
    • Weight changes or, in the case of children, not meeting expected weight gain c39
    • Signs of self-abuse (eg, scars, bruises, lacerations) c40c41c42c43
  • Psychiatric signs
    • Any of the following types of abnormal affect:
      • Blunted (flat) or constricted c44c45
      • Irritable c46
      • Labile c47
      • Inappropriate c48
    • Abnormal psychomotor activity is often seen
      • Psychomotor retardation c49
        • Indicated by slowed or absent spontaneous movement c50
        • Typical of the fall/winter pattern c51c52
      • Psychomotor agitation c53
        • Patient appears restless

Causes and Risk Factors


  • Condition is thought to be caused by combination of factors that likely includer6:
    • Circadian phase delay or advance, probably affecting depressive symptoms via changes in melatonin levels c54
    • Abnormal retinal sensitivity to light c55
    • Neurotransmitter dysfunction c56
    • Genetic variations affecting circadian rhythms
    • Abnormal serotonin levels c57

Risk factors and/or associations

  • Particularly common in women during childbearing years r6c58
  • More common in women, with reported female to male ratio of 4 to 1 r6c59
  • Variants of the melanopsin gene (OPN4) could predispose some individuals r7c60
  • Having a first-degree relative who has experienced depressive symptoms increases the risk r6c61
Other risk factors/associations
  • Residence at mid to high latitudes r8c62
  • Severe visual impairment r9c63
  • Chronic tinnitus r10c64

Diagnostic Procedures

Primary diagnostic tools r6

  • History and physical examination c65
  • Depression scales, inventories, and questionnaires
    • Hamilton Depression Rating Scale and Beck Depression Inventory are commonly used

Laboratory r2

  • Laboratory tests play no role in diagnosing the condition, but are used to rule out common conditions, such as substance abuser6 (urine screen for drugs of abuse) and hypothyroidismr11 (TSH and thyroxine levels)

Other diagnostic tools

  • Hamilton Depression Rating Scale r12c66
    • Recurrent major depressive disorder with a seasonal pattern is designated seasonal affective disorder on this scale
    • Completed by examiner while observing patient
  • Beck Depression Inventory r13c67
    • Questionnaire answered by patient
    • Available in standard 21-question format, or as an abridged 7-question format appropriate for screening in the primary care setting
    • Elucidates severity, intensity, and depth of typical major depression symptoms

Differential Diagnosis

Most common

  • Hypothyroidism c68d1
    • Disorder characterized by inadequate synthesis and secretion of thyroid hormones r11
    • Similarities r11
      • Patient has low energy or fatigue and may have depressed mood
      • Hypophagia
      • Weight gain
      • Hypersomnia
    • Differences
      • TSH level is elevated r11
      • Free thyroid hormones (especially free thyroxine) are decreased r11
      • Usually there is no seasonal pattern or predictable annual occurrence, although seasonal course with summertime improvement has been seen with hypothyroidism r6
    • Definitive diagnosis is made via thyroid panel (TSH and thyroxine levels) r11
  • Major depressive disorder without a seasonal pattern r2c69d2
    • Disorder defined by presence of depressed/irritable mood and/or anhedonia, plus 4 or more of the following features for at least 2 consecutive weeks:
      • Sleep changes
      • Decreased interest (anhedonia)
      • Increased feelings of guilt
      • Decreased energy
      • Impaired concentration
      • Appetite changes
      • Psychomotor changes
      • Suicidal thoughts or actions
    • Similar to recurrent major depressive disorder with a seasonal pattern in the history of major depressive episodes defined by presence of 5 or more of the same features; different in that there is no seasonal pattern or predictable annual occurrence
    • Diagnosis is entirely clinical, based mostly on history
  • Bipolar disorder r2c70d3
    • Mood disorder characterized by cycling between depressive and manic or hypomanic episodes
      • Bipolar I includes manic episodes, with an episode defined by the following criteria:
        • Persistent elevated, expansive, or irritable mood for at least 1 week (or less than 1 week if hospitalization is required)
        • 3 or more of the following symptoms present during mood disturbance (4 or more required if mood is irritable and not elevated or expansive):
          • Inflated self-esteem or grandiosity
          • Decreased need for sleep
          • Increased talkativeness
          • Flight of ideas or racing thoughts
          • Distractibility
          • Increase in goal-directed activity or psychomotor agitation
          • Increase in risky behavior
        • Symptoms don’t meet criteria for a mixed episode, in which both manic and major depressive episode criteria are present
        • Level of severity sufficient to cause social or occupational impairment, hospitalization, or psychotic features
        • Symptoms are not due to substance use or a medical condition
      • Bipolar II includes hypomanic episodes
        • Hypomanic episode is defined by same criteria that define a manic episode, except level of severity is not sufficient to cause social or occupational impairment, hospitalization, or psychotic features
    • Similar to recurrent major depressive disorder with a seasonal pattern in that patient meets criteria for at least 1 major depressive episode; different in that there is no seasonal pattern or predictable annual occurrence
    • Diagnosis is entirely clinical, based mostly on history
  • Cyclothymic disorder r14c71
    • Characterized by mood cycling that does not meet diagnostic criteria for major depressive disorder or bipolar disorders I and II
    • Similar to recurrent major depressive disorder with a seasonal pattern in that major depressive disorder symptoms come and go; different in that there is no seasonal pattern or predictable annual occurrence
    • Diagnosis is entirely clinical, based mostly on history
  • Substance-related disorder r15c72
    • Condition resulting from abuse of alcohol or drugs
    • Similar to recurrent major depressive disorder with a seasonal pattern in that both can manifest with changes in mood, social and occupational impairment, and similar symptoms
    • Different in that use of a substance can be identified and established via admission by patient, observation of others, or medical tests (eg, urine screening for drugs of abuse)
    • Definitive diagnosis is based on history, physical examination, and appropriate substance abuse work-up, which includes:
      • Questioning regarding quantity of alcohol consumed and/or types and quantities of drugs used
      • Assays on urine samples for alcohol, opioids, benzodiazepines, cocaine/stimulants, cannabis, and other drugs of abuse
    • Following a positive screening test result, conversation with patient is focused on the substance use to elicit DSM-5 symptoms of a substance use disorder, which include:
      • Tolerance
      • Withdrawal
      • Using more drugs than intended
      • Failed efforts to cut down or quit
      • Spending a lot of time related to use
      • Craving
      • Failure to fulfill important life roles
      • Giving up important life activities
      • Use in hazardous situations
      • Continued use in spite of either negative physical/psychological problems, or social/interpersonal consequences



  • Abatement of depression symptoms
  • Recognition of any suicidal or homicidal potential
  • Identification and management of medical complications of depression, such as malnutrition and nonadherence to medical treatment
  • Return of patient to normal social/occupational activities and function
  • Prevention of recurrent episodes


Admission criteria

  • Admission to an inpatient psychiatric unit is warranted when patient cannot care for self or is a danger to self or others, owing to either of the followingr16:
    • Suicidal or homicidal ideation
      • Previous suicide attempts or violence can strengthen the case for admission when case is equivocal
    • Presence of psychotic symptoms

Recommendations for specialist referral

  • Consult psychiatrist for any of the following:
    • Suicidal or homicidal ideation or attempts
    • Alcohol or drug dependence or abuse
    • Comorbid psychosis, suspected bipolar disorder, or personality or developmental disorders
    • Dementia, delirium, or confusion
    • Lack of response to light therapy

Treatment Options

Principal treatment modalities consist of the following:

  • Light therapy (also called bright light therapy) r17
    • Primary treatment modality
  • Cognitive behavioral therapy r18
    • Efficacy is comparable with light therapy
    • Acceptable treatment option; may have prophylactic benefits for subsequent years
  • Second generation antidepressant drugs, especially selective serotonergic reuptake inhibitors r4
    • Second line treatment
    • Some evidence, albeit limited in quality and quantity, shows effectiveness for fluoxetiner19 and sertraliner20
      • Light therapy and fluoxetine are comparably effective and well tolerated; other clinical factors, such as patient preference, might guide the selection of treatment r4

Drug therapy

  • Selective serotonin reuptake inhibitors r6c73
    • Bupropion (extended-release bupropion hydrochloride tablets; e.g., Wellbutrin XL): r21
      • Bupropion Hydrochloride Oral tablet, extended release 24 hour [Depression/Mood Disorders]; Adults: Initiate in the autumn with 150 mg PO once daily in the AM; titrate after 7 days to target dose of 300 mg PO once daily in the AM. Continue through winter, then taper and discontinue in early spring. Individualize regimen to patient's historical pattern of SAD episodes. For those receiving 300 mg/day, taper to 150 mg/day prior to discontinuation. Total daily doses above 300 mg/day were not evaluated in SAD clinical trials.
    • Fluoxetine r4c74
      • Fluoxetine Hydrochloride Oral tablet [Depression/Mood Disorders]; Adults: 20 mg/day PO initially. May increase after several weeks by 10 to 20 mg as needed and tolerated. Consider lower dosages for geriatric adults. Max: 80 mg/day PO. May divide daily dose into 2 doses (e.g., morning and noon) if the dosage is 20 mg/day or more.
    • Sertraline r20c75
      • Sertraline Hydrochloride Oral tablet; Adults: 50 mg PO once daily. A lower initial dose (25 mg PO once daily) may be used to minimize adverse effects. If necessary, increase at intervals of not less than 1 week. Max: 200 mg/day PO. The length of treatment should be determined on an individual basis. Periodically reassess the need for continued treatment.

Nondrug and supportive care

The following nondrug therapies are the most effective types of therapy for this conditionr6:

  • Light therapy
  • Cognitive behavioral therapy
Light therapy r22c76
General explanation
  • Just after awakening, patient is positioned next to a special light-emitting device to receive 5000 lux hours per day
    • Usually, this is achieved using a 10,000 lux device for 30 minutes
    • Patient can engage in any activity while receiving treatment, but must keep eyes within the needed distance from the light source as indicated by the instructions for the particular device
    • Abatement of major depressive symptoms within a few weeks (usually within 2 weeks) indicates that treatment is effective
  • Recurrent major depressive disorder with fall/winter seasonal pattern
  • Patients with bipolar disorder receiving light therapy are at greater risk of developing manic or hypomanic episodes; however, light therapy is not a contraindication for these patients
Cognitive behavioral therapy r6c77
General explanation
  • Psychotherapy that is highly structured, focused, short-term, and therapist-patient collaborative; consists of the following principal components:
    • Functional analysis
      • Patients are taught to recognize irrational thoughts and assumptions, and irrational connections between assumptions, thoughts, and behaviors that underlie, exacerbate, and perpetuate depression
      • Patients are taught to track, stop, and redirect thoughts with the aim of different behaviors, thereby changing the emotional response that underlies the depression
    • Skills training
      • Patients are taught to unlearn behaviors that underlie and exacerbate depression and to learn new behaviors via a variety of techniques, including:
        • Exposure and desensitization
        • Learning exercises and home assignments
        • Adoption of pleasurable activities during the problematic time of the year
  • Generally, cognitive behavioral therapy shows results in a few weeks or a few months; resolution of depressive symptoms within that time period suggests the treatment has been effective
  • Recurrent major depressive disorder with seasonal pattern in any of the following scenarios:
    • Light therapy is inadequate in abating symptoms
    • Patient refuses light therapy or is not adherent
    • Light therapy is not appropriate, due to nonwinter seasonality of the recurrent depression
    • Patient is eager to begin cognitive behavioral therapy alongside light therapy


  • Major psychiatric disorders c78
    • Bipolar disorders I and II c79c80
      • Typically require additional treatment alongside light therapy or cognitive behavioral therapy
    • Cyclothymic disorders c81
      • Patients can have a seasonal element (treatable with light therapy) plus depressive features throughout the year, requiring continuous psychotherapy or medication
    • Anxiety disorders, including obsessive-compulsive disorder c82c83
      • May alter the plan for any cognitive behavioral therapy, requiring it to be longer or more intense
    • Eating disorders c84
      • Can exacerbate or hide the changes in appetite of recurrent major depressive disorder with a seasonal pattern, thereby making the diagnosis more challenging
    • Depression during pregnancy or the postpartum period c85c86
      • Symptoms of depression are common in the postpartum period, and this period may correlate with the season during which a patient with recurrent depressive disorder suffers symptoms
      • Cognitive behavioral therapy may be the best first option; effects of light therapy during pregnancy are largely unknown
      • Selective serotonin reuptake inhibitors entail a treatment dilemma: some data show neurobehavioral and long-term cognitive problems among children of women who were treated with those drugs during pregnancy, but untreated maternal depression also carries serious risks for both mother and child
  • Personality and developmental disorders c87c88
    • May alter the plan for any cognitive behavioral therapy, requiring it to be longer or more intense
    • In the case of certain personality disorders, such as borderline personality disorder, presence as a comorbid condition may require dialectic behavioral therapy
      • Dialectic behavioral therapy is a modified form of cognitive behavioral therapy that is focused on changing behaviors that are particularly common in borderline personality disorder (eg, suicidal ideation, self-harm, substance abuse)


  • Schedule patients for regular follow-up and use a standardized scale to measure response to therapy, as this has been shown to improve outcomes r23
    • Hamilton Depression Rating Scale or Beck Depression Inventory are useful for monitoring, as are other standardized depression scales (eg, the Patient Health Questionnaire [PHQ-9])

Complications and Prognosis


  • Suicide c89
  • Impaired social and occupational performance c90c91
  • Disrupted interpersonal relations c92
  • Substance abuse c93

Prognosis r12

  • Response to light therapy within 2 weeks of initiation predicts a favorable outcome
  • A meta-analysis supported the efficacy of light therapy in both seasonal and nonseasonal depression, and reported effect sizes that were equivalent to those in most trials of antidepressants r24
  • Improvement of atypical symptoms (eg, hypersomnolence, increased appetite, carbohydrate craving) after 1 hour of light therapy correlates with improvement of disorder after 2 weeks of therapy

Screening and Prevention

Screening c94


  • Consider initiating light therapy in early autumn for patients with fall/winter seasonality r6c95c96
    • Evidence supporting light therapy for prevention is limited due to small studies and methodologic flaws; requires discussion with patient r25
  • Bupropion is the only medication shown to be effective in preventing recurrence of seasonal affective disorder, but adverse effects, such as headaches, nausea, and insomnia, are commonly observed r26
  • Lifestyle adjustments are recommended by some experts, including: r6c97
    • Exercising more often c98
    • Increasing light in the home c99
    • Practicing relaxation and stress management techniques c100c101
    • Spending more time outside c102
    • Visiting sunnier, warmer climates c103
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