Lack of enthusiasm can have various causes, ranging in severity from 'minor' to 'serious'. Finding the true cause means ruling out or confirming each possibility – in other words, diagnosis.
Diagnosis is usually a complex process due to the sheer number of possible causes and related symptoms. In order to diagnose lack of enthusiasm, we could:
|Caffeine Intoxication||5%||Ruled out|
How excitable/enthusiastic are you generally?
Possible responses:→ Indifferent / hard to stimulate
→ Average / don't know
→ Excitable, easily stimulated
Nervous excitability can be a symptom of mercury toxicity.