**1. Introduction**

Bariatric surgery is the most effective option for individuals with severe obesity. It includes several surgical procedures, commonly divided into restrictive such as Laparoscopic Adjustable Gastric Banding, Banded Gastric Bypass, Sleeve Gastrectomy, malabsorptive such as Biliopancreatic Diversion, Intragastric Balloon, and mixed procedures such as Roux-en-Y- Gastric Bypass, Mini Gastric Bypass, and Gastric Bypass.

Bariatric surgery procedures lead to substantial weight loss and marked improvements in obesity-related comorbidities as well as quality of life. Nonetheless, there is a significant variation in long-term weight loss maintenance and weight regain has been partially attributed to psychological factors.

For these reasons, the pre-operative evaluation of the psychological conditions of the candidates for bariatric interventions is required in order to achieve the

desired post-operative outcomes for a long time. In addition, adjunctive pre or postoperative psychosocial interventions are highly recommended for bariatric patients [1, 2] with psychological difficulties.

Within this chapter, the main components of pre-surgical psychological assessment for bariatric candidates will be discussed, including procedures and instruments involved. Moreover, an overview of the principal characteristics of pre/ post-surgical psychological support will be provided.
