Psychomimetic agents

Chemical agents that consistently produce changes in thought, perception and mood, without causing any major disturbances in the autonomic nervous system or other serious disability, are classified as psychomimetic agents. This group of agents includes substances which, when administered in low doses (<10 mg), cause conditions similar to psychotic disorders or other symptoms emanating from the central nervous system, such as loss of feeling, paralysis, hallucinations, etc.

During World War II, the US military investigated a wide range of possible non-lethal, psychomimetic chemical incapacitating agents such as lysergic acid diethylamide (LSD) and marijuana derivatives as well as several glycolate anticholinergics. One of the anticholinergic compounds, 3-quinuclidinyl benzilate, was developed and weaponized in the 1960s as a new chemical agent and assigned the NATO code BZ. Studies continued in the US until at least 1965.

The common signs and symptoms produced by the psychomimetic agents are:

• restlessness, dizziness, failure to obey orders, confusion, erratic behavior, unsteadiness on the feet, vomiting
• dryness of the mouth, tachycardia at rest, elevated temperature, flushing of the face, blurred vision, dilation of the pupils, slurred or nonsensical speech, hallucinatory behavior, disrobing, mumbling, incoherence,  stupor and coma
• inappropriate smiling or laughter, irrational fear, distractibility, difficulty expressing self, perceptual distortions and phobias

Psychotomimetic agents are generally now not considered to be likely chemical warfare agents. They were experimented with in the 1950s-70s, but tend to be unstable and are difficult to deliver in sufficient concentration to be effective, as well as being very unpredictable in their effects.

3-Quinuclidinyl Benzilate [3-Quinuclidinyl benzilate, 3-Chinuclidylbenzilate, 3-quinuclidinylbenzilate, BZ, EA2277, agent 15] - C₂₁H₂₃NO₃

A a crystalline solid, odourless or with a fruity or benzene-like odour. It is classified as a hallucinogenic chemical warfare agent. 3-Quinuclidinyl Benzilate usually is disseminated as an aerosol, and the primary route of absorption is through the respiratory system. Absorption also can occur through the skin or gastrointestinal tract. Mild to moderate intoxication can cause elevated body temperature, dry mouth, dry skin, low urine output, flushing of skin, dilated pupils, inability to focus on near objects, blurred vision, and rapid heart rate (this may later reduce to a normal or slow heart rate). Other effects include disorientation, altered level of consciousness, delusions, hallucinations, poor judgment and insight (denial of illness), short attention span, distractibility, impaired short-term memory, slurred speech, involuntary repetition of behaviours, loss of coordination, variability in behavior (e.g., between quiet and restless states), and muscle weakness.

Severe intoxication: Dose-dependent decrease in consciousness level from drowsiness through sedation to stupor and coma, hallucinations and combative agitation, serious alterations in heart rhythm and serious alterations in levels of ions in biological fluids (electrolyte disturbances).

Lysergic acid diethylamide [LSD] - C₂₀H₂₅N₃O

Effects may occur within 30 minutes of exposure, they typically include altered thoughts, feelings, and awareness  surroundings, seeing or hearing things that do not exist. Dilated pupils, increased blood pressure, and increased body temperature are typical. Physical effects (e.g. dilated pupils, mild hypertension and occasionally raised body temperature) appear first. Sensory-perceptual changes are the outstanding features of LSD. Visual disturbances are perceived with eyes closed or open and may consist of geometric shapes or figures in patterns. Flashes of intense colour are seen and stable objects may appear to move and dissolve. Cross-sensory perception (synaesthesia) such as 'coloured hearing' can occur where sounds such as voices or music evoke perception of particular colours or shapes. The perception of time may appear to slow down.

Phencyclidine [PCP, angel dust, Phenylcyclohexylpiperidine]  - C₁₇H₂₅N

A mind-altering drug that may lead to hallucinations. It is considered a dissociative drug, leading to a distortion of sights, colours, sounds, self, and one's environment. Low to moderate doses may cause: numbness of the extremities, slurred speech, and loss of coordination may be accompanied by a sense of strength and invulnerability, a blank stare, rapid and involuntary eye movements, and an exaggerated gait are among the more observable effects, auditory hallucinations, image distortion, severe mood disorders, and amnesia may also occur, acute anxiety and a feeling of impending doom, paranoia, violent hostility, a psychoses indistinguishable from schizophrenia. Physiological effects of low to moderate doses  include: slight increase in breathing rate. rise in blood pressure and pulse rate, shallow respiration, flushing and profuse sweating occurs. Physiological effects of high doses include: hypotension, bradycardia, bradypnea, nausea, vomiting, blurred vision, flicking up and down of the eyes, drooling, loss of balance and dizziness, violence, self-harm and suicide.