Generally speaking, drugs that stimulate 5-HT2C, D2, or beta3-adrenergic receptors are more likely to be associated with either short-term weight loss or no weight gain.1-4 On the other hand, drugs that block 5-HT2C, H1, and D2 receptors are more likely to be associated with short-term weight gain.1-5 Since long-term actions of psychotropic drugs are often the opposite of short-term actions,5 one might expect these patterns to be reversed in long-term administration. What has more commonly been observed is that the short-term weight loss experienced by patients in acute treatment is not sustained when they are in maintenance treatment, and those who initially experience short-term weight gain have more profound weight gain with long-term treatment (see Table).