For most medications: yes. But psychotropic medications actually do alter the endocrine system (e.g. beta-3 receptors, which convert fat to energy) and can cause weight gain that is unrelated to calorie consumption. This is not to defend the coworker (who probably wouldn't be talking about her medications if she had psychosis), but it's useful to know. If you go on that class of medications, you'll probably gain weight no matter how good of shitlord/lady you are...and it can be a substantial amount.