The major downside associated with the use of barbiturates is their high potential for addiction. Barbiturates are central nervous system depressants that can create a sedative effect, leading to their potential misuse and dependency. Over time, individuals may require larger doses to achieve the same effects due to tolerance, which can escalate the risk of addiction and associated negative health consequences.
As these substances can lead to physical and psychological dependence, they pose a significant danger if not used under strict medical supervision. This risk is exacerbated by the withdrawal symptoms that might occur if use is abruptly discontinued, further complicating the user’s ability to stop taking them.
Other aspects, such as their availability, short-term effectiveness, and rebound effects, are relevant but not as critically impactful in the context of addiction potential. The addictive nature of barbiturates fundamentally affects the user's health and well-being, making it the most significant downside.