Key takeaways

  • Depression is characterized by a persistent low mood that can affect quality of life. If symptoms usually only occur in the winter months, it may be seasonal affective disorder (SAD), or major depressive disorder with seasonal pattern.
  • The exact causes of depression and seasonal depression are unclear, but reduced sunlight exposure may play a role in developing SAD.
  • Some treatments, such as talking therapy and antidepressants, may help manage depression and SAD. Light therapy and vitamin D supplements may also help treat SAD.

Depression can be constant, or it can come and go. If symptoms tend to appear in the colder months and then improve around springtime, you may be experiencing seasonal affective disorder (SAD), or “winter depression.”

Although less common, some people also experience seasonal depression in the warmer months.

Read on to learn more about depression and SAD, including the symptoms and causes, treatment options, and more.

Various symptoms can occur in both depression and SAD. You may experience some or all of the following:

  • persistent low mood or feeling sad
  • irritability
  • restlessness
  • feeling hopeless
  • reduced energy
  • fatigue
  • losing interest in activities you usually find enjoyable
  • problems concentrating
  • changes in sleep quality
  • appetite changes
  • headaches
  • physical aches and pains
  • thoughts of death or suicide

Additionally, SAD can cause symptoms such as :

  • social withdrawal
  • oversleeping (hypersomnia)
  • overeating

Symptoms of SAD typically last for around 4 to 5 months of the year. They usually begin in late autumn or early winter, and tend to improve by early spring.

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

  • Call or text the 988 Suicide and Crisis Lifeline at 988 or chat at 988lifeline.org. Caring counselors are available to listen and provide free and confidential support 24/7.
  • Text HOME to the Crisis Text Line at 741741 to connect with a volunteer crisis counselor for free and confidential support 24/7.
  • Not in the United States? Find a helpline in your country with Befrienders Worldwide.
  • Call 911 or your local emergency services number if you feel safe to do so.

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you’re not in the same household, stay on the phone with them until help arrives.

It is unclear exactly what causes depression and SAD.

Factors that may increase the likelihood of depression include:

  • emotional stress
  • family history
  • hormonal changes, such as with menopause
  • pregnancy
  • having a chronic condition

Possible triggers for SAD include:

  • changes in your circadian rhythm, your internal body clock
  • higher levels of melatonin due to an increased number of darker hours
  • problems with regulating serotonin
  • feeling uncomfortable in colder weather

Your doctor can work with you to help identify any possible triggers for depression or SAD.

To assist with reaching an accurate diagnosis, your doctor may begin by asking questions about your symptoms, and they may ask you to fill out a questionnaire about the frequency and severity of your symptoms.

For a diagnosis of depression, you will usually need to experience symptoms most days for at least 2 weeks.

For a SAD diagnosis, you will usually need to have experienced the symptoms during the winter months for at least 2 consecutive years.

Some treatments may help both depression and SAD. Examples that may help include:

Steps you can take to help manage symptoms include:

  • getting enough physical activity or exercise
  • trying to go to bed and wake up at the same time each day
  • eating a balanced diet, aiming for smaller meals more frequently if you have a reduced appetite
  • spending time with friends or loved ones

Treatments that may help with SAD include light therapy and vitamin D supplements.

The National Institute of Mental Health explains that around 21 million adults in the United States experience at least one major depressive episode. This is around 8.3% of all adults.

According to the American Psychiatric Association, more than 5% of people in the United States experience SAD.

In around 40% of SAD cases, symptoms may continue into the summer months. This may lead to a diagnosis of major depressive disorder or another mental health condition.

It is important to contact a doctor as soon as you have concerns about depression or SAD. It can take some time to find the right treatment for you, so working with your doctor as soon as possible to create a treatment plan is crucial.

Your doctor will likely refer you to a mental health professional. You can speak with them to learn more about talking therapies and ways to manage symptoms when they occur.

Depression and seasonal affective disorder (SAD) both cause persistent feelings of sadness. They can also cause symptoms such as restlessness, irritability, fatigue, loss of interest, and more.

Symptoms of SAD can also include oversleeping, overeating, and social withdrawal. To diagnose seasonal depression, you will usually need to experience symptoms each winter for two consecutive years. If symptoms occur in the warmer months instead, you may be experiencing “summer SAD.”

Speak with a doctor as soon as there are concerns about depression or SAD. They can help create a suitable treatment plan, which may include medications such as antidepressants, talking therapy, light therapy, and vitamin D supplements.