**Question:** Which of the following is not a feature of drug dependence -

A. Tolerance
B. Withdrawal symptoms
C. Compulsive drug-seeking behavior
D. Increased drug-seeking behavior

**Core Concept:** Drug dependence is a state of altered physiological and psychological dependence on a substance, leading to a range of symptoms upon withdrawal. The concept is crucial in understanding the pathophysiology of substance abuse disorders and the rationale for pharmacological interventions.

**Why the Correct Answer is Right:** Option A, Tolerance, is a significant feature of drug dependence. It refers to the need for increased doses of the drug to achieve the same pharmacological effect over time as the body adapts to the substance. This adaptation can lead to over-reliance on the drug and contribute to the progression of dependence.

Option B, Withdrawal symptoms, is also a key aspect of drug dependence. Withdrawal symptoms occur when the substance is discontinued or its concentration in the body decreases, and can range from mild to severe depending on the substance involved.

Option C, Compulsive drug-seeking behavior, describes the individual's inability to control their drug use, despite experiencing adverse consequences. This behavior is a hallmark of drug dependence and is often used to differentiate it from recreational use or abuse.

Option D, Increased drug-seeking behavior, is indeed a feature of drug dependence. However, it is not exclusive to drug dependence as it can also occur in abuse or recreational drug use. The core feature that sets drug dependence apart is the loss of control over drug intake.

**Why Each Wrong Option is Incorrect:** Option A, Tolerance, is not incorrect; however, it is included in the correct answer as it is a common misconception that tolerance is the sole feature of drug dependence.

Option B, Withdrawal symptoms, is a correct feature but is included in the correct answer to emphasize that withdrawal symptoms are not exclusive to drug dependence.

Option C, Compulsive drug-seeking behavior, is a core feature of drug dependence, distinguishing it from abuse or recreational use.

Option D, Increased drug-seeking behavior, is indeed a feature of drug dependence but is also relevant in abuse or recreational drug use. The core feature that sets drug dependence apart is the loss of control over drug intake.

**Clinical Pearl:** When dealing with patients with substance use disorders, it is crucial to assess for features such as tolerance, withdrawal symptoms, compulsive drug-seeking behavior, and increased drug-seeking behavior to differentiate between abuse, dependence, and addiction. Understanding these features helps guide appropriate treatment strategies and prognosis.