Freud's work with his patients convinced him that many nervous ailments are ______

Hallucinogenic drugs, such as LSD, produce their effects via an action on the neurotransmitter

a. dopamine. b. GABA. c. endorphin. d. acetylcholine. e. serotonin.

One significant limitation of the cross-sectional design is called the "cohort effect.". This relates to the fact that a. experience is confounded with participation in the study. b. age and experience are confounded

c. genetics and experience are confounded. d. reliable statistics cannot be computed for cohort groups.