Optional medical device diagnostics – depending on the results of the history, physical examination, laboratory diagnostics, and obligatory medical device diagnostics – for differential diagnostic clarification.
- Cardiovascular diagnostics
- Exercise ECG (electrocardiogram during exercise, that is, under physical activity/exercise ergometry).
- Cardio-computed tomography (cardio-CT) – early detection of coronary vascular calcification.
- Doppler sonography of the vessels supplying the brain.
- Magnetic resonance imaging (MRI; computer-assisted cross-sectional imaging method (using magnetic fields, i.e., without X-rays); particularly well suited for changes in the spinal cord and brain) – patients with depression have a reduced concentration of the neurotransmitter GABA – gamma-amino-butyric acid – in their brains; this can be visualized by applying a magnetic field with an MRI scanner (method is still in the evaluation stage)
- Positron emission tomography (PET; nuclear medicine method that allows cross-sectional imaging of living organisms by visualizing the distribution patterns of weak radioactive substances) – Glucose consumption in the insula affects the effect of therapy for major depression:
- Decreased glucose consumption in the insula compared with the rest of the cerebrum → good chance of success with cognitive behavioral therapy (CBT).
- Increased glucose consumption in the insula → good chance of success with antidepressants.
- Polysomnography (sleep laboratory; measurement of various body functions during sleep that provide information about sleep quality) – exclusion of sleep apnea; in case of resistance to therapy, the possible cause of sleep apnea should be considered.Note: In one study, 14% of patients with major depression had previously undiagnosed sleep apnea (apnea-hypopnea index (AHI) > 10 ).
Further notes
- Computerized analysis of EEG leads could potentially predict in the future whether a patient with major depression will respond to drug therapy. An algorithm developed for this purpose was able to identify those patients who improved with 8 weeks of therapy with sertraline (an antidepressant from the selective serotonin reuptake inhibitor (SSRI) group).
