The literature on an association between organophosphate (OP) toxicity and depression or suicide is scarce. An interrelation exists among populations exposed to OPs, acute OP toxicity, neurobehavioral effects, depression, suicide, and fatality. Acute OP toxicity is characterized by the cholinergic syndrome with systemic and central nervous system effects. Organophosphate-induced neurobehavioral effects result in depression. A potential risk of depression and suicide exists in farm workers exposed to OPs. The sociodemographics of depression include age, gender, race, geographic region, social factors, economics, psychiatric disorders, medical conditions, and hereditary factors. Suicide is a major consequence of depression, with multiple sociodemographic risk factors. Developing countries have a higher incidence of OP toxicity, with limited information on the prevalence of depression. In these countries, the incidence of suicide is high, affecting more females. Suicide is more prevalent in rural areas, and in farming communities, commonly with ingestion of OPs. In industrialized countries, the incidence of OP toxicity is lower, but the prevalence of depression is higher. Suicide rates are lower in industrialized countries, affecting more males, the urban population, and farming communities. Other lethal methods of suicide, such as hanging, firearms, electrocution, and drug overdose are more common in industrialized countries. A potential risk of depression or suicide certainly exists from OP toxicity, largely depending on the epidemiology or sociodemographics of these disorders. Scientific evidence shows that the association between environmental toxicology and psychiatry has important public health implications.