Which neurotransmitter that is altered by the ingestion of PCP, is thought to play a role in schizophrenia?

A researcher wants to collect information about how the sex-role identities of 1st-, 3rd-, 5th-, and 7th-grade children differ. What type of research design is she likely to use?

a) cohort b) longitudinal c) correlational d) cross-sectional

Which of the following is NOT mentioned in the text as being effectively treated by cognitive therapy?

a) dissociative identity disorder b) schizophrenia c) insomnia d) bulimia