Ask depressed patients about brain fog to ensure melancholia is not mist

This study aims to highlight cognitive 'brain fog' as a key depression sub-typing symptom, being weighted to melancholic (as against non-melancholic) depression and note its common persistence after episode remission.

This paper weights clinical observation but considers several salient overview papers and research findings.

While 'brain fog' is intrinsically non-specific in that it has multiple causes, when assessed as a second-order depressive sub-typing symptom, it has seemingly distinctive specificity to the melancholic sub-type, with many patients with melancholia resonating with such a descriptor question. As it may persist (albeit attenuated) after episode remission, psychostimulant medication may be of benefit in some patients.

In the clinical assessment and differential diagnosis of those with a depressive disorder, inquiring into 'brain fog' can have distinct diagnostic benefit in differentiating melancholic and non-melancholic depression.