SAD - Diagnosing seasonal affective disorder

Visit your GP if you have the symptoms of seasonal affective disorder (SAD). Effective treatments are available if you're diagnosed with the condition.

Your GP may carry out a psychological assessment to check your mental health. During the assessment, you may be asked questions about:

• your mood
• your lifestyle
• your eating patterns
• your sleeping patterns
• any seasonal changes in your thoughts and behaviour
• whether there's anything in your personal history that may contribute to a depressive disorder, such as child abuse
• whether there's anything in your family history that may contribute to a depressive disorder, such as a family history of depression

Your GP may also carry out a brief physical examination to check for any other possible causes of your symptoms.

Diagnosing depression

Two major classification systems are used to diagnose depression. Your GP may use one of these systems to help diagnose SAD. The classification systems take into consideration:

• your symptoms
• the severity of your symptoms
• how long your symptoms last
• how your symptoms progress
• to what extent your symptoms prevent you from carrying out normal activities

You may be diagnosed with a level of depression that's mild, moderate or severe. 

Seasonal depression

SAD can be difficult to diagnose because there are many other types of depression that have similar symptoms. It may therefore take several years before you and your GP realise that your symptoms are forming a regular pattern.

A diagnosis of SAD will depend on whether:

• you've had symptoms during the same seasons for two or more years in a row
• your periods of depression are followed by periods without depression
• there are any other obvious explanations or causes for your seasonal mood changes