Preface

It is generally believed that drug abuse can cause severe long-lasting changes in the neural network contributing to the development of addiction. Profound states of addiction may be established in brains with repetitive usage, despite its damage to the brain. Dopamine plays a very significant role in addiction to drugs. Under normal conditions, in neural communication between neurons, the presynaptic neuron releases dopamine into the synapse. At the postsynaptic neurons, there are receptors which receive the dopamine. Usually, any left-out dopamine molecule is recycled back to the presynaptic neuron by the dopamine transporters. If any drug blocks the dopamine transporter it is unable to take the dopamine back from the synaptic cleft leading to the continuous firing of neurons. As per Drug Enforcement Administration (DEA) and the Controlled Substances Act (CSA) reports, heroin is a Schedule I drug. Heroin causes addiction to the brain like any other addictive substance. Heroine use affects not only neurotransmitters but also the hormonal systems in an irreversible way. In healthy young people, the use of MDMA can lead to cognitive decline when abused with cannabis. MDMA causes hyponatremia and hyponatremia-associated deaths. This book deals with the harmful effects of drugs on brain and cognitive functions. I wish our readers can be satisfied with many questions and feel excited to find the answer to the research questions on the etiology of neurological sequelae of drug abuse in this book.