OUTLINE

Objective

Introduction

Epidemiology

Models of development of substance use disorder and addiction

Conclusion

References

INTRODUCTION

The term “substance use disorder” in DSM-5 and “disorders due to psychoactive drug use” in ICD-10 refers to conditions arising from the misuse of alcohol, psychoactive drugs, or other volatile substances resulting in significant impairment in all aspects of an individuals life.⁽¹⁾

Addiction is a neuropsychological disorder characterized by a persistent and an intense urge to engage in certain behaviors, often usage of a drug despite substantial harm and other negative consequences. ⁽²⁾

This concept could be a complicated issue and over the years scientists have created theories to try and explain or find a linkage between drug use and its victim’s life.

A BRIEF OVERVIEW OF THE NEUROBIOLOGY OF ADDICTION

THE REWARD SYSTEM (CIRCUIT) { MESOLIMBIC PATHWAY & MESOCORTICAL PATHWAY}

One of the most important circuit in the brain.

Its where we feel emotions and also process these emotions

It drives our behavior towards pleasurable stimuli (food, exercise, sex, monetary reward or even from a psychoactive drug.)

It also drives us from painful ones that require more energy e.g. conflict etc.

In response to a cue or in anticipation of a reward the brain produces dopamine in the Ventra tegmental area and this is released into the nucleus accumbens.

Psychoactive substances has the ability to flood the nucleus accumbens with dopamine.

The hippocampus lays down memories of this rapid sense of pleasure and satisfaction and the amygdala creates a conditioned response to this stimuli.

Chronic use overtime will result in reduced sensitivity of receptors to dopamine and a downward regulation of the reward circuit.