As of March 2025, a search on ClinicalTrials.gov for recruiting interventional studies specifically for FXS highlights several pharmacological approaches focused on (1) GABA pathways deficits, (2) glutamatergic N-methyl-D-aspartate (NMDA) receptor dysfunction, (3) targeting reduced cyclic adenosine monophosphate (cAMP) levels with predominantly phosphodiesterase-4D (PDE4D) inhibitors, (4) activation of AMP-activated protein kinase (AMPK), and (5) modulation of the endocannabinoid (EC) system. Here, PDE4D is linked to fragile X syndrome.