According to the WHO report approximately 450 million people suffer from mental and behavioural disorder. Depression is one of the most common neurodegenerative disorders which arise due to the imbalance of neurotransmitters release at the synaptic cleft. A large number of synthetic drugs are being used as standard treatment for depression, they have many adverse effects that a limit the therapeutic treatment. Traditionally herbs are used for the treatment of depression which may offer advantage in terms of safety and tolerability, possibly by improvement in patient compliance. Herbal drugs are more commonly used because these have small amount of chemicals, these produced less side effects than standard drugs. Overall, this chapter presented an overview of the research that has been done on the many herbs, Mechanism of action involving monoamine reuptake, neuroreceptor binding and channel transporter function, and neural communication or HPA modulation. Several pharmaceutical companies are working on “triple” reuptake inhibitors that stop all three monoamines from being reabsorbed. Studies into the interplay of monoamine systems with other neurotransmitters (e.g., CRF, neurokinins, glutamate, and GABA etc.) will aid in the development of realistic, integrated neurochemical models of depression.

Aim: The main aim of present study to assess the depression and various neurotransmitters involved in it with their evaluating models. Background: Depression is a common ailment that can be recurrent or even become chronic. According to the National Service Framework for Mental Health (released in 1999 by the Department of Health), people with depression should continue to be treated primarily in primary care settings. Despite mounting evidence that general practitioners could do a better job of detecting and treating depression, little research has been done on the perspectives of general practitioners who treat patients who are depressed. Depression (major depressive disorder) is a widespread and significant medical condition that has a negative impact on feeling, thinking, and behaviour. Objectives: The primary goal of this study was to gather data on depression, as well as to discuss several methods for evaluating antidepressant drug response based on physical activities and neurotransmitters. Method: Antidepressant activity of various medications can be tested using two different types of studies, including in-vivo and in-vitro, according to the review. Result: Depression is characterized by a persistent sense of sadness, insomnia, lack of concentration, slowness in activity, restlessness, social isolation and a loss of interest that prevents you from doing normal things. There are several types of depression, with symptoms ranging from mild to severe. Depression is caused by a combination of factors and conditions, rather than a single factor. Major depression is a mental condition marked by feelings of inadequacy, hopelessness, decreased activity, sadness and mood swings, which seriously disrupt and negatively affect a person's life, sometimes suicide is attempted. The quest for a better understanding of the causes of depression and the development of more effective treatments is critical. According to clinical and preclinical research, stress appears to be a crucial mediator in the pathophysiology of depression. Using experimental models, depression may be assessed based on several physical parameters such as locomotor activity, rearing, defecation, and the number of centre square entries (In-vivo and In-vitro). Biological parameters may also be used to locate it.

Aim: The goal of this study is to determine that treating depression with Piperine and Bupropion HCl in combination is more successful than with these medicines alone. Background: -Depression is a mood disorder referred to as the collection of conditions connected with the elevation or lowering of the mood marked by melancholy, loss of interest in activities, with little or no social life. Despite the enormous amount of research, efficient treatment of depression is still one of the most desired aspects of managing depression. Objective: This study is focused on establishing the effectiveness of combinational therapy through animal behavioral models. Method: The study was initiated by acclimatizing animals for one week in conventional laboratory settings. Depression was induced in animals through the forced swim method. Animal behavioral models were utilized to investigate the efficacy of the drug combination for the treatment of depression. Result: Positive results were reported for the group treated with the drug combination and were significant (p < 0.05) to every other group that participated in the study. No mortality was found in any of the study groups. Conclusion: This study supports the efficacy of combinational therapy of Piperine and Bupropion HCl for treating depression.

Background: Serotonin is a neurotransmitter that regulates neuronal activity and a variety of cognitive functions, and medicines that target serotonin receptors are frequently utilized in psychiatry and neurology. Clinical and preclinical research on the role of serotonin in major depressive disorder is growing. These findings demonstrate the intricacy of serotonin transmission across multiple receptors, in a variety of brain areas, and across the lifespan. The serotonin transporter's significance in major depressive disorder has been highlighted in gene-environment association studies, as well as its participation in the mechanism of the most successful antidepressant medications, selective serotonin reuptake inhibitors. While most of the 15 known serotonin receptors have been linked to depression or depressive-like behaviour, the serotonin 1A (5-HT) and 1B (5-HT) receptors have received the most attention. Objectives: The primary goal of this study is to review the antidepressant effect of herbal medications by modifying serotonin receptors in the future. Result: Human brain imaging and genetic studies suggest that 5-HT and 5-HT receptors play a role in major depressive disorder and antidepressant treatment response. The availability of tissue-specific and inducible knockout mice lines in rodents has allowed for the detection of 5-HT and 5-HT receptor involvement throughout development and in cell-type specific ways. It may be found that herbal drugs will be effective as the serotonin reuptake inhibitors. Conclusion: This and other future preclinical pharmacology studies show that these receptors' autoreceptor and heteroreceptor populations play different roles in modulating depression-related behaviour and antidepressant responses, as well as having different functions during early postnatal development versus adulthood. According to analysis of our research findings, alkaloids may have some therapeutic promise as natural antidepressants. Given their widespread distribution in nature, alkaloids might be a cheap way to treat depression.