Would you like to make the sentence shorter?

The research on the safety of drug X has found that the adverse reaction in central nervous system caused by drug A is significantly different to that caused by drug Y.

oristarA wrote:

The research on the safety of drug X has found that the adverse reaction in central nervous system caused by drug A is significantly different to that caused by drug Y.

Research has found that drug X and drug A produce significantly different adverse reactions in the central nervous system.

I'm generally in favor of shorter sentences, but I don't see any unnecessary verbiage in this example. Shorter is only better if it conveys the same meaning.