The symptoms of seasonal affective disorder (SAD) are similar to those of normal depression, but they occur at a particular time each year.

Most people's symptoms start in the autumn or winter and improve in the spring.

The symptoms of SAD are usually fairly mild at the start of the autumn and get worse as the winter progresses and the amount of sunlight decreases. However, the nature and severity of the symptoms will vary from person to person.

Some people with SAD experience recurring episodes of unipolar depression, while others may find they experience mild episodes of bipolar depression.

Unipolar depression is where you only experience depressive symptoms. Bipolar depression involves depressed periods (lows) followed by manic periods (highs) where you feel happy, energetic and much more sociable.

SAD symptoms

As with all forms of depression, the main symptoms of SAD include a low mood and a loss of pleasure or interest in normal everyday activities. Other depressive symptoms can include:

• feeling irritable
• feelings of despair
• feelings of guilt and worthlessness
• low self-esteem
• indecisiveness
• tearfulness
• feeling stressed or anxious
• a reduced sex drive

In addition to the above symptoms, you may also:

• be less active than normal
• feel tired and sleep more than normal (hypersomnia)
• feel lethargic (lacking in energy)
• find it difficult to concentrate
• have an increased appetite and eat more than usual (hyperphagia)

For many people, SAD can be difficult to live with and it can have a significant effect on day-to-day life. However, it can be successfully treated.

Read more about treating seasonal affective disorder.