Screening for depression
Like blood pressure, cholesterol and glycaemia, mood should be routinely monitored in primary care because it is a health risk factor for other conditions, in addition to its direct effects on wellbeing. If a GP wishes to ensure that a patient is not left undiagnosed and if there is the means in the clinic to address patients’ needs (see Referring to psychoeducation and /or psychotherapy), GPs could consider routine depression screening e.g. of all new patients.
There are many screening instruments for depression.
The WHO-5 can be used as a first-line screening measure for depression. It is a well-validated measure for depression screening in primary care. It is easy to use and short with only five items, all positively framed (without mentioning “depression” explicitly). If a patient’s score is less than or equal to 13, they may be experiencing a depressive episode (80% sensitivity). In these patients, the diagnosis should be further explored by the GP.
Another screening tool for use in primary care is the PHQ-9, which allows the GP to identify the severity of the depressive symptoms and degree of functional impairment. This tool is also well-validated and is sensitive to change over time. A score of 5-9 suggests mild depression, 10-14 suggests moderate depression, and 15+ indicates severe depression. Particular attention should be paid to affirmative responses to item 9 (“thoughts that you would be better off dead or of hurting yourself in some way”).
The most important challenges in diagnosing depression are two-fold:
- Differentiate it from "feeling blue" that is, from normal or transient depressive feelings;
- Do not downplay the impact of even light symptoms of depression, which may be treatable;
There are several aspects of a depressive episode that indicate how severe it is, including apathy, emotional numbness, feelings of guilt, severe hopelessness, daily fluctuation in mood, suicidality, psychotic symptoms, and changes in personality.
Interested in improving your diagnostic skills? Email gillian.karwig<at>ucc.ie, stating interest in attending related training.
When reaching a diagnosis of depression, mood disorder due to organic conditions must be considered. Somatic and/or iatrogenic depression must be excluded and treated:
- endocrinological dysfunction such as hyper- or hypothyroidism, hyperparathyroidism, hypercortisolism;
- neurological disorders;
- viral infections;
- cancer and paraneoplastic syndromes;
- autoimmune reaction;
- pharmacological causes such as corticotherapy, benzodiazepine abuse and dependency, etc.