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Seasonal Affective Disorder

Describes depressive symptoms that may recur with the seasons and provides a basic framework for assessment and management.

seasonal affective disorder · SADS · sad

MONDO:0000694Public QA completeSource-bound · 5

Disease at a glance

Start with the essentials, then explore the patient and research views.

Public revision · 4f5b882d2955

Disease Category
Seasonal affective disorder is a depressive disorder that recurs with the seasons, typically beginning in late autumn or winter and improving in spring and summer.
Core Mechanism
The exact cause is unknown, and changes in sunlight exposure and fluctuations in serotonin, melatonin, and vitamin D have been studied as related factors.
Main Causes and Related Factors
Seasonal changes in natural light can affect the biological clocks and sleep-wake rhythms of some individuals, potentially contributing to mood changes.
Representative Manifestations
Symptoms may include feelings of depression, pessimistic outlook, feelings of worthlessness or irritability, decreased interest or pleasure, decreased energy, changes in sleep, carbohydrate cravings, and weight gain.
Individual Variability
It may be more common in women, young people, individuals living in regions far from the equator, and those with a history or family history of depression.
Diagnosis
Symptoms may follow a pattern of onset in a specific season and remission in another, with some experiencing depressive episodes in spring or summer.
Management
Diagnosis is made clinically by comprehensively evaluating the recurrent association between seasons and symptoms, current depressive symptoms, past medical history, and lifestyle patterns, while also considering other causes.
Treatment/Research Status
Since diagnosis cannot be confirmed by seasonality alone, differential diagnosis must include major depressive disorder, bipolar disorder, sleep disorders, internal medicine diseases, and medication effects.
Evidence Reading
Management can be carried out by combining light therapy, psychotherapy, pharmacotherapy, and lifestyle rhythm regulation, considering the severity of symptoms, seasonal patterns, safety risks, and individual preferences.
Key Points to Note
Light therapy is introduced as the primary treatment, and in some cases, antidepressants or talk therapy are used alone or in conjunction with light therapy.

For patients and families

A structured guide for understanding the disease and preparing for clinical conversations.

Overview

Seasonal affective disorder is a depressive disorder that recurs with the seasons, typically beginning in late autumn or winter and improving in spring and summer.

Symptoms may include feelings of depression, pessimistic outlook, feelings of worthlessness or irritability, decreased interest or pleasure, decreased energy, changes in sleep, carbohydrate cravings, and weight gain.

How the Disease Works

The exact cause is unknown, and changes in sunlight exposure and fluctuations in serotonin, melatonin, and vitamin D have been studied as related factors.

Seasonal changes in natural light can affect the biological clocks and sleep-wake rhythms of some individuals, potentially contributing to mood changes.

Presentation Varies by Individual

It may be more common in women, young people, individuals living in regions far from the equator, and those with a history or family history of depression.

The broad framework for diagnosis and management

Symptoms may follow a pattern of onset in a specific season and remission in another, with some experiencing depressive episodes in spring or summer.

Diagnosis is made clinically by comprehensively evaluating the recurrent association between seasons and symptoms, current depressive symptoms, past medical history, and lifestyle patterns, while also considering other causes.

Current status of treatment

Since diagnosis cannot be confirmed by seasonality alone, differential diagnosis must include major depressive disorder, bipolar disorder, sleep disorders, internal medicine diseases, and medication effects.

Management can be carried out by combining light therapy, psychotherapy, pharmacotherapy, and lifestyle rhythm regulation, considering the severity of symptoms, seasonal patterns, safety risks, and individual preferences.

Light therapy is introduced as the primary treatment, and in some cases, antidepressants or talk therapy are used alone or in conjunction with light therapy.

How to interpret clinical trials

There are records of intervention trial registrations addressing the prevention of seasonal affective disorder, but the registration or completion of a trial alone cannot be used to determine treatment effectiveness or whether it constitutes standard care.

Key points to verify in clinical consultations

In clinical care, verify the timing of symptom onset and offset, changes in sleep, appetite, and activity, past depressive or manic symptoms, and the appropriateness of medications and light therapy. If there are thoughts of suicide or immediate danger, do not stay alone; contact the local emergency medical system or healthcare providers immediately.

Medical Guidance

This material is for educational purposes only and does not replace individual diagnosis or treatment guidance.

Evidence and sources

A trial registry status does not establish efficacy or regulatory approval.