What causes Delhiites to kill at the drop of a hat? Experts believe it is the lack of impulse control. The city police on Thursday reported two separate incidents in which three people were killed for trivial reasons.“Usually people who take such drastic steps when they are angry, have problems with impulse control and an extremely low threshold for frustrations. They cannot restrain themselves, have no guilt in the heat of the moment, and forget about any consequences that their actions may attract,” said Dr Sudheer Khandelwal, former head of the department of psychiatry at All India Institute of Medical Sciences (AIIMS).These incidents do not happen in the void though. “A person who can kill impulsively will have a history of activities in which they have come in conflict with the society or the law,” said Dr Khandelwal. “These actions may not have been drastic and so they may have gone unreported,” said Dr Khandelwal, who currently works as a senior consultant of psychiatry at Holy Family hospital.Road rage to fight over food bill: Why Delhi is on short fuseIn such cases, experts believe, that there is usually a history of some mood or personality disorder that remained untreated. “Often people ignore symptoms of a psychiatric disorder thinking that it is a personality trait and these disorders remain undiagnosed. It is better to seek treatment than wait for such incidents. Family members must look out for hyperactivity in children, aggression, restlessness, irritability, lack of impulse control, and self-harm,” said Dr Sameer Malhotra, director of mental health and behavioural sciences at Delhi’s Max Hospitals.The stress of living in a city adds to it. “The city life is full of stress – getting stuck in a traffic jam, standing in long queues – a need to prove oneself if the person has come to the city for a job and a lack of social support. All these add to the existing condition, which may then result in the person taking a drastic step,” said Dr Malhotra.