organophosphate ( op ) poisoning is the most common poisoning in developing countries with half of the admissions to the emergency with poisoning being due to these compounds . in recent years , various investigations have demonstrated that op exposure causes neurobehavioral changes after both acute and chronic exposure . the central nervous system effects of op exposure have received less attention in the medical literature than peripheral effects . tabershaw and cooper noted that certain patients displayed vague mental changes such as irritability , memory disturbances and dream abnormalities for several months after their apparent recovery from op poisoning . gershon and shaw described the development of schizophrenic and depressive symptoms after exposure to op insecticides . neurological manifestations like choreoathetosis , opisthotonos , torticollis , facial grimacing , extrapyramidal symptoms , and typical parkinsonism following op exposure have been reported . other behavioral disturbances such as learning deficits , increased anxiety , diminished activity and impulsivity have also been reported . we are reporting a case of 33-year - old female who developed manic episode following acute op poisoning . a. , 33-year - old hindu married female presented to psychiatry outpatient department ( opd ) with complaints of over talkativeness , big talks , irritability , over familiarity , decreased sleep and increased physical activity for last 7 days . on evaluation there was history of accidental ingestion of op insecticide chlorpyrifos 5 days before the onset of psychiatric symptoms . within 4 hours of ingestion of the insecticide , symptoms of acute op poisoning developed and the patient was admitted to the hospital suffering from severe abdominal cramps , hyper salivation and excessive sweating . she was treated with atropine and recovered rapidly from the acute muscarinic and nicotinic symptoms . serum cholinesterase levels were low ( 650 u / l ; normal : 3500 - 8500 hematological and biochemical indices were normal as was computed tomography of the brain and eeg . she was treated with tablet olanzapine 10 mg per day and her symptoms improved significantly within next 10 days . it may be that in op exposure the excess acetylcholine merely upsets the balance of transmitter systems active in cortical functions or alternatively leads to presynaptic inhibition of acetylcholine release via a negative feedback loop . another mechanism that may be postulated to explain these symptoms is dopamine receptor hypersensitivity as seen after neuroleptic administration . in the corpus striatum , a balance exists between dopamine as the inhibitory and acetylcholine as the excitatory system . the dopaminergic system inhibits the cholinergic neurons and vice versa . excessive acetylcholine , as can occur in op exposure , suppresses dopaminergic activity , and hypersensitivity of postsynaptic dopaminergic neurons may result . schizophrenic psychosis or depressive illness may occur after obvious acute op intoxication or may follow chronic subliminal exposure . recent studies have shown that acute op intoxication may cause neurobehavioral deficits by producing inflammatory response . these neurobehavioral deficits may be due to direct neurotoxicity of proinflammatory cytokines ( e.g. tnfa , il-1b , and interleukin-6 ) or via interactions between these proinflammatory cytokines and excitotoxic glutamatergic pathways or due to excessive activation of nmda receptors leading to neurodegeneration . recent evidences also suggest that the cholinesterase - based mechanism of op toxicity can not alone account for the neuropsychiatric symptoms . op interactions with proteins involved in fundamental neuronal processes such as axonal transport , neurotrophin support , and mitochondrial function leading to these neuropsychiatric symptoms . although the acute muscarinic and nicotinic side - effects of op poisoning are well known and easily recognized , but neuropsychiatric changes are rarely reported . this has important clinical implication for any community such as in india , where agriculture forms a large part of the economy and hence insecticide use is very common .
organophosphate poisoning is the most common poisoning in developing countries . 
 although the acute muscarinic and nicotinic side - effects of organophosphate poisoning are well known and easily recognized , but neuropsychiatric changes are rarely reported . 
 we are reporting a case of a 33-year - old female who developed manic episode following acute organophosphate poisoning .