This paper is the forty-sixth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2023 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug and alcohol abuse (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

UNASSIGNED: Cervical screening could be an appropriate routine moment to provide female smokers with tailored stop smoking advice. In Dutch general practice, cervical smears are performed by practice assistants.
UNASSIGNED: This study was performed in preparation for a randomised trial to identify potential barriers and enablers for a brief stop smoking strategy performed by trained practice assistants after routine cervical screening.
UNASSIGNED: Between December 2016 and March 2017 three focus group meetings were held with ten practice assistants, three nurses, and six general practitioners to explore their views and expectations towards the proposed approach. We analysed data using thematic analysis. Identified factors are presented within the framework of the Social-Ecological Model.
UNASSIGNED: Potential barriers and enablers were identified at individual, interpersonal, and workplace levels. Practice assistants, nurses and GPs did not consider assistants to have a role in stop smoking care. They believed it is feasible to register smoking status but had reservations towards providing advice by assistants, for which knowledge and skills are needed. Practice assistants\' own beliefs about smokers and smokers\' response to stop smoking advice might influence how assistants and smokers interact. An explanation of why advice is given could help, provided assistants have enough time and experience with the smear. The nurses\' availability and general practitioners\' view on prevention might affect the delivery of the strategy by the assistant.
UNASSIGNED: At individual, interpersonal, and workplace levels, several factors could influence the provision of a stop smoking strategy by a practice assistant.