CACNA1C and psychiatric disorder: Some patients with psychiatric disorders also take antihypertensive drugs to treat their mental illness.[28] Calcium-channel blockers are widely used to treat hypertension because they are more effective than other types of antihypertensive agents.[29]CACNA1C gene encodes protein is expressed in neurons and other electrically excitable tissues (heart, smooth muscle), sensory, and endocrine cells,[30] which play an important role in regulating BP.