For this reason, researchers have become more interested in identifying the effects of methamphetamine on human brains. In animal tests, methamphetamine has been shown to destroy receptors for dopamine, a neurochemical essential to many brain functions. In addition, tests of methamphetamine users showed decreased motor skills and memory impairments, even when people had stopped using methamphetamine 11 months prior to participating in the study. Based on these findings, the researchers warn that methamphetamine seems to damage human dopamine receptors and therefore that methamphetamine users face a future of cognitive, neurological, and motor difficulties. Because methamphetamine is highly addictive, the researchers also point out that doctors, psychologists, and the media need to alert people to the long-term negative consequences of methamphetamine use.
Some people have a stereotype of older people as depressed and grumpy.
These researchers studied four generations of people over 23 years and found that participants experienced a decrease in the amount of negative emotion as they aged. Indicating that old people are not destined to experience less positive emotion, extraverted older adults generally were immune to the decrease in positive emotions. Stanley Milgram carried out studies of obedience to authority that remain the most talked-about social psychological experiments in the history of social psychology. This week's Research Report discusses an association between dieting and starting smoking among adolescent girls. This week's News Brief on older people and emotion indicates that older people experience less negative emotion than do younger people.