If you have the symptoms of seasonal affective disorder (SAD), visit your GP. If you are diagnosed with the condition, effective treatments are available.
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 is anything in your personal history that may contribute to a depressive disorder, such as child abuse
- whether there is 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 consider:
- the symptoms that you have
- how severe your symptoms are
- 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 is mild, moderate or severe.
Seasonal depression
SAD is often difficult to diagnose because there are many other types of depression that have similar symptoms. Therefore, it may 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 have 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.



