The force of gravity is the weakest at the equator because of the centrifugal force caused by the Earth's rotation and because points on the equator are furthest from the center of the Earth. The force of gravity varies with latitude and increases from about 9.780 m/s2 at the Equator to about 9.832 m/s2 at the poles.
Also, pharmacological therapies such as sedative-hypnotics or antidepressants have been helpful in reducing the incidence of sleepwalking in some people. Sleepwalking is common in children and is usually outgrown over time, especially as the amount of deep sleep decreases.
However, many antidepressants can worsen sleep. Because of the activating effects of some drugs, for example imipramine, desipramine, fluoxetine, paroxetine, venlafaxine, reboxetine and bupropion, many patients who take them have to be co-prescribed with sleep-promoting agents to improve sleep.lthough none of the reported changes in sleep are specific to depression, many of them, for example increased REM density and reduced amount of SWS in the first sleep cycle, are used as biological markers for research on depression and in the development of antidepressant drugs.