This is the golden line because I think it is a really shocking statistic. The fact that 40% of research not published to the public just shows that drug companies care more about profits instead of the well being of their consumers. This suggests why Hari experienced negative side effects when he was taking the antidepressants because the drug company did not publish any results showing those side effects. This would also affect doctors when prescribing their patients because they would not know about the side effects and making them believe that the medication is all good for their patients.
Another reason is because of the thought that the side effects may put the consumers on other medications. Some of the drugs can cause side effects and may require other forms of medication. Hari also mentioned in his book that companies publish their research only if it is good for their own company or bad for their rival companies. The company would not publish results of research if it was bad for the product they were trying to sell which just makes no sense from a business perspective. If this case is true it would put the consumers in a cycle of drug consumption which will only increase the profits of the drug companies.