Group 1 - AbbVie has agreed to acquire Gilgamesh Pharmaceuticals' experimental antidepressant drug for up to $1.2 billion, focusing on the candidate drug bretisilocin for treating major depressive disorder [1][2] - The acquisition emphasizes AbbVie's commitment to expanding psychiatric care through investment in novel treatment methods, particularly for patients unresponsive to existing therapies [1] - Gilgamesh will spin off its other research projects into a new entity, Gilgamesh Pharma Inc., while maintaining the licensing option from their previous collaboration [2] Group 2 - There is growing support for psychedelic drugs in treating major depressive disorder, with over 20 million adults in the U.S. affected, and approximately 30% of them not responding to current treatments [2] - Gilgamesh is developing neuroplastogens, a new generation of psychedelic drugs that act quickly without causing hallucinations, with positive results reported for bretisilocin in major depressive disorder studies [2] - Historical caution from large pharmaceutical companies regarding psychedelic drugs due to regulatory concerns makes this transaction particularly significant [2]