"These days, we daren't let our children play outside. We're suspicious of strangers. Security cameras are everywhere," The Telegraph quoted him as saying.
He added: "We seem to have entered an age of paranoia. And the indications are that things may only get worse."
Freeman found that one in four people have paranoid thoughts regularly.
In his opinion, a new era of suspiciousness has been triggered by a combination of factors, which include the increasing number of people living in cities, the physical environment in which we live, growing wealth inequalities and the reporting of crime and terrorism.
In fact, the levels of paranoia are much higher in cities as compared to rural areas. This is the first time the world's urban population has outnumbered the rural.
Dr Freeman said: "Social bonds are much looser in cities than in smaller, rural communities where ready-made, relatively stable support networks exist.
"Social isolation, a frequent drawback to urban life, is closely associated with paranoid thoughts. In the UK nearly four times as many people live alone than 50 years ago. Increasing paranoia is certainly one more challenge posed by galloping urbanisation."
Further, he said that the news coverage given to crime is far ahead of coverage of 'real killers' such as heart disease, cancer and road accidents, which promotes a culture of paranoia.