What is Seasonal Affective Disorder (SAD)?

Seasonal affective disorder (SAD) is a type of depression associated with seasonal changes – it starts and ends at the same time every year. It is common for people with SAD to experience symptoms starting in the fall and continuing into the winter months, making them feel energetic and happy. These symptoms usually disappear in the spring and summer. Occasionally, SAD causes depression in the spring or summer and resolves in the fall or winter months.

Causes of Seasonal Affective Disorder

The cause of SAD is still under investigation, but it appears to be linked to the biological clock (sleep-wake cycle) that is regulated by light. When light enters the retina, it triggers chemical reactions in the brain. This happens in the pineal gland, which is located in the centre of the brain. Our clocks are controlled by the hormones that are produced there. The hormone melatonin is produced here, and it causes sleepiness. Melatonin production may be impaired in people with winter depression, but research has not confirmed this. It is also likely that there is an imbalance in serotonin levels in people with SAD, just like people with “normal” depression. This neurotransmitter controls, among other things, the feeling of well-being and mood.

Symptoms of SAD

In most cases, symptoms of seasonal affective disorder appear in late fall or winter and disappear during the sunny spring and summer. Rarely, people with different patterns have symptoms that start in the spring or summer. In any case, symptoms may develop slowly and worsen over time.

Signs and symptoms of SAD may include:

• Feeling apathetic, sad, or depressed most days, almost every day
• Uninterested in your usual activities
• Having less energy and feeling tired
• Have trouble sleeping a lot
• Carbohydrate cravings, overeating and weight gain
• You have difficulty concentrating
• Feelings of hopelessness, worthlessness, or guilt
• Having suicidal thoughts

Fall and Winter SAD

The following are symptoms specific to winter-onset SAD, also known as winter depression:

• Sleeping too much
• Increased cravings for carbohydrate-rich foods
• Weight gain
• Fatigue or weakness

Spring and summer SAD

A person suffering from summer-onset seasonal affective disorder may experience the following symptoms:

• lack of sleep
• Low appetite
• Weight loss
• Increased anxiety and irritability
• Increased stress

Seasonal changes and bipolar disorder

Seasonal affective disorder is more likely to occur in people with bipolar disorder. In some people with bipolar disorder, episodes of mania are associated with specific periods. For example, spring and summer can bring symptoms of mania or mild mania (hypomania), anxiety, restlessness, and depression. They can also become depressed during the fall and winter months.

Diagnosis of SAD

A mental health professional or health care provider may have difficulty diagnosing seasonal affective disorder even after a thorough evaluation. This is because there are many mental health conditions that can cause similar symptoms, including depression and anxiety disorders. To help diagnose SAD, a thorough examination includes:

• Physical examination. Your health care provider may perform a physical exam and ask in-depth questions about your health. In some cases, depression can be linked to underlying physical health problems.
• Laboratory analysis. For example, your healthcare provider may do a blood test called a complete blood count (CBC) or test your thyroid to make sure it’s working properly.
• Psychological assessment. To check for signs of depression, your health care provider or mental health professional asks you questions about your symptoms, thoughts, feelings, and behaviours. You can fill out a questionnaire to help you answer these questions.

Treatment of SAD

Treatment for seasonal affective disorder may include heat therapy, psychotherapy, and medication. If you have bipolar disorder, talk to your health care provider and a mental health professional – knowing this is important when prescribing painkillers or antidepressants. Both of these treatments can trigger manic episodes.

Light therapy

In light therapy, also called phototherapy, you sit a few feet away from a special light box, so you are exposed to bright light within the first hour of waking each day. Light therapy mimics outdoor heat and appears to make changes in mood-related brain chemistry.

Light therapy is one of the first treatments for early-onset SAD. It usually starts working within a few days to a few weeks and causes few side effects. Research on light therapy is limited, but it seems to be effective for most people in reducing the symptoms of SAD. Before buying a light box, discuss with your health care provider which one is best for you. You should also familiarize yourself with the different types and options for buying a high-quality, safe, and effective product. Also ask how and when to use the light box.

Psychotherapy

Treatment for SAD can also be achieved through psychotherapy, also known as talk therapy. The following benefits can be obtained from cognitive behavioural therapy:

• Learn effective ways to cope with SAD, especially reducing avoidance behaviours and organizing meaningful activities
• Recognise and refrain from thinking negative thoughts and change your behaviours when they cause you to feel unhappy
• Learn to manage stress
• Adopt healthy habits, such as increasing your physical activity and improving your sleep habits

Drug therapy

In severe cases of SAD, antidepressants may be beneficial.

An extended-release version of the antidepressant bupropion (Wellbutrin XL, Aplenzin) can help prevent depression in people with a history of SAD. Other antidepressants can also be used to treat SAD.

Your health care provider may recommend starting treatment with an antidepressant before your symptoms usually start each year. He or she may also recommend that you continue taking the antidepressant for as long as your symptoms resolve.

Keep in mind that it may take several weeks to experience the full benefits of an antidepressant. Also, you can try different drugs before finding one that works best for you and has minimal side effects.

When to go to the doctor

It is normal to have days when you are tired. And if you’ve been feeling down for days and can’t motivate yourself to do activities you normally enjoy, see your health care provider. This is especially important if your sleep patterns and appetite have changed, if you are turning to alcohol for comfort or relaxation, or if you feel like you have no hope or have suicidal thoughts.