A Very Troublesome Symptom of Major (Clinical) Depression and Manic Depression

Psychomotor retardation or psychomotor impairment comprises a slowing down of thought and a reduction of physical movements in an individual. This is most commonly seen in people with major depression, as well as in the depressed phase of bipolar disorder, and is also associated with the adverse effects of certain drugs such as benzodiazepines. Particularly in inpatient settings, psychomotor retardation can require increased nursing care to ensure adequate food and fluid intake as well as sufficient personal care. Informed consent for treatment is more difficult to achieve when this is present.
Psychomotor retardation is also referred to as "motormental retardation", commonly seen in depression and bipolar disorder.
Some examples of psychomotor retardation may include the following:

1. Unaccountable difficulty with carrying out what are usually considered "automatic" or "mundane" self-care tasks for healthy people (i.e., without depressive illness), such as taking a shower, putting on clothes, self-grooming, preparing food, brushing teeth and exercising.
2. Actual physical difficulty performing activities that normally would require little thought or effort, such as walking up a flight of stairs, getting out of bed, preparing meals and clearing dishes from the table, household chores, returning phone calls, etc.
3. Tasks requiring mobility suddenly or gradually and inexplicably seem to be "impossible". Activities such as shopping, getting groceries, caring for the daily needs of one's children, and meeting the demands pertaining to employment or school are commonly affected. Individuals experiencing these symptoms typically sense that something is wrong, and may be confused over their inability to perform these tasks.
4. Activities usually requiring little mental effort can become challenging. Balancing one's checkbook, making a shopping list, making decisions about mundane tasks, (such as deciding what errands need to be done) are often difficult.

Via:  Wikipedia