Researchers suggest people who claim to be "spiritual" but not religious are often struggling to cope mentally and suffered problems including abnormal eating conditions, drug abuse, anxiety disorder, phobias and neurosis.
They were also more likely than others to be taking medication for mental health problems, the 'Daily Mail' reported.
"Our main finding is that people who had a spiritual understanding of life had worse mental health than those with an understanding that was neither religious nor spiritual," Professor Michael King, from University College London, and his fellow researchers said.
The study was based on a survey of 7,403 randomly selected men and women in England who were questioned about their spiritual and religious beliefs, and mental state.
Thirty-five per cent described themselves as "religious", meaning they attended a church, mosque, synagogue or temple.
A further 19 per cent claimed to have spiritual beliefs or experiences without following a specific religion, while 46 per cent were neither religious nor spiritual.
Of the different groups, spiritual people were 50 per cent more likely to have a generalised anxiety disorder and 72 per cent more likely to suffer from a phobia.
They also had a 77 per cent higher chance of being dependent on drugs and were 37 per cent more at risk of neurotic disorder.
Researchers said spirituality was also associated with a 40 per cent greater likelihood of receiving treatment with psychotropic drugs.
The study found that individuals of religious faith and those with none experienced equal levels of mental problems. However, there were fewer problems with drugs or alcohol among the faithful.
Unlike previous studies in the US, the new research found no clear relationship between religious belief and happiness.
"We conclude that there is increasing evidence that people who profess spiritual beliefs in the absence of a religious framework are more vulnerable to mental disorder.
"The nature of this association needs greater examination in qualitative and in prospective quantitative research," the researchers said.
