Zolpidem has also been studied in persistent vegetative states with unclear effect. A 2017 systematic review concluded that while there is preliminary evidence of benefit for treating disorders of movement and consciousness other than insomnia (including Parkinsons disease), more research is needed. More recent research has found zolpidem treatment to be effective in the short term, but only in a small proportion of cases (estimated at around 5%) and only when the brain injury is of a specific type. Tolerance to the beneficial effects also develops rapidly, and so for these reasons while zolpidem may sometimes be used as a "last resort" treatment, it has numerous disadvantages and research continues into novel treatments that might provide the same kind of benefits in a larger proportion of patients, and with a more sustained benefit.Animal studies in FDA files for zolpidem showed a dose dependent increase in some types of tumors, although the studies were too small to reach statistical significance.
Frustration or over-gratification was said to result in an oral fixation and in an oral type of character, characterized by feeling dependent on others for nurturance and by behaviours representative of the oral stage. Later psychoanalytic theories shifted the focus from a drive-based approach of dependency to the recognition of the importance of early relationships and establishing separation from these early caregivers, in which the exchanges between the caregiver and the child become internalized, and the nature of these interactions becomes part of the concepts of the self and of others. References
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