chronic pain, but its utility for this purpose is controversial. Pregabalin is generally not regarded as efficacious in the treatment of acute pain. In trials examining the utility of pregabalin for the treatment of acute post-surgical pain, no effect on overall pain levels was observed, but people did require less morphine and had fewer opioid-related side effects. Several possible mechanisms for pain improvement have been discussed. Anxiety disorders Pregabalin is moderately effective and is safe for treatment of generalized anxiety disorder. It is also effective for the short- and long-term treatment of social anxiety disorder and in reducing preoperative anxiety. However there is concern regarding pregabalin's off-label use due to the lack of strong scientific evidence for its efficacy in multiple conditions and its proven side effects. The World Federation of Biological Psychiatry recommends pregabalin as one of several first line agents for the treatment of generalized anxiety disorder, but recommends other agents such as SSRIs as first line treatment for obsessive–compulsive disorder and post-traumatic stress disorder (PTSD). For PTSD, pregabalin as complimentary treatment seems to be effective. Generalized anxiety disorder Pregabalin appears to have anxiolytic effects similar to benzodiazepines with less risk of dependence. The effects of pregabalin appear after one week of use, and are similar in effectiveness to lorazepam, alprazolam, and venlafaxine, but pregabalin has demonstrated superiority by producing more consistent therapeutic effects for psychosomatic anxiety symptoms. Long-term trials have shown continued effectiveness without the development of tolerance, and, in addition, unlike benzodiazepines, it has a beneficial effect on sleep and sleep architecture, characterized by the enhancement of slow-wave sleep. It produces less severe cognitive and psychomotor impairment compared to benzodiazepines. A 2019 review found that pregabalin reduces symptoms, and was generally well tolerated. Other uses Although pregabalin is sometimes prescribed for people with bipolar disorder there is no evidence showing that it is effective. There is no evidence and significant risk in using pregabalin for sciatica and low back pain. Evidence of benefit in alcohol withdrawal as well as withdrawal from certain other drugs is limited as of 2016. One study concluded that pregabalin may be a useful prophylactic medication for migraines. Adverse effects Exposure to pregabalin is associated with weight gain, sleepiness and fatigue, dizziness, vertigo, leg swelling, disturbed vision, loss of coordination, and euphoria. It has an adverse effect profile similar to other central nervous system depressants. Even though pregabalin is a depressant and