All the following are features of LSD intoxication except
**Core Concept**
LSD (Lysergic Acid Diethylamide) is a potent serotonin receptor agonist that causes profound alterations in perception, mood, and cognition. Its effects are primarily mediated through the 5-HT2A receptor subtype in the brain.
**Why the Correct Answer is Right**
LSD intoxication is characterized by intense visual hallucinations, altered perception of time and space, and a range of mood changes, including euphoria, anxiety, and paranoia. The 5-HT2A receptor agonism leads to increased serotonin activity in various brain regions, particularly in areas involved in visual processing and emotional regulation. This results in the characteristic "trippy" effects of LSD, including synesthesia (e.g., seeing sounds as colors) and changes in body perception.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided, as it is the question stem. However, it should list a feature of LSD intoxication, such as altered perception of time or visual hallucinations.
**Option B:** Increased heart rate and blood pressure are not specific features of LSD intoxication. While some users may experience tachycardia and hypertension, these effects are more commonly associated with other substances, such as cocaine or amphetamines.
**Option C:** Sedation is not a feature of LSD intoxication. In fact, LSD is known to cause increased alertness and arousal, which can manifest as hyperactivity, agitation, or even aggression in some cases.
**Clinical Pearl / High-Yield Fact**
LSD is a potent serotonin receptor agonist that can cause profound alterations in perception and mood. Its effects are primarily mediated through the 5-HT2A receptor subtype in the brain, and it is often associated with intense visual hallucinations and altered body perception.
**Correct Answer: B. Increased heart rate and blood pressure are not specific features of LSD intoxication.**