Wiktionary
overstudy
vb. To study excessively
Usage examples of "overstudy".
The symptoms were prostration, sleeplessness, exhaustion, over-fatigue from mental trouble, overstudy and anxiety, indigestion, dyspepsia, constipation, headache, inability to concentrate the mind, general lassitude, melancholia, backache and pains from the top of my head to the sole of my feet.