The teams are working with a number of teenagers and young adults who have psychotic symptoms such as hallucinations, strange ideas, confused thinking and acute mood swings.

Scientists believe that heavy use of cannabis, especially in teenagers and young adults, increases the risk of developing a continuing psychosis, such as schizophrenia.

Oliver Beatson, a member of the East Sussex Youth Cabinet, said, "I think that using cannabis starts off as a social recreation. People try it for a new experience either unaware of the risks, or prepared to pay the consequences, thinking, 'What's the chance of it going wrong for me?'

"This risk is admittedly fairly low — but it rises considerably if stronger forms of cannabis, such as skunk, are used. In East Sussex, skunk has become the cannabis of choice for many people, as opposed to less concentrated forms. There are many different strengths and variations, such as resin and herbal options, and it's easy to under or overestimate their effects."

Councillor Bill Bentley, lead member for adult social care at ESCC, said, "The chemical in cannabis which makes people feel 'high' or 'stoned' is called tetra-hydro-cannabinol (THC). Skunk has a much higher level of THC — and as a result is far more dangerous to your mental health.

"In young adults and teenagers, when the brain is still developing, the risk is that this class C drug will have serious long-term effects on your mental health, requiring medical treatment and possibly even admission to hospital. We need to get the message out there that for some young people heavy use of skunk can mess up your life.

"It's not always obvious when people are developing a psychosis. Some of the warning signs may be losing contact with friends, not wanting to go out or do anything, being suspicious of people, having panic attacks, saying strange things or getting distracted easily."

Nick Yeo, the chief executive of East Sussex Downs and Weald and Hastings and Rother primary care trusts, said, "If you think you, your son or daughter, friend or partner may be developing mental health problems, it's important to get help early on, to stop things becoming more serious.

"This means talking to your doctor for advice. Then, if a serious mental illness is diagnosed, your doctor will call in one of the community mental health teams — made up of nurses, social workers, psychiatrists, doctors, occupational therapists and psychologists. These professionals work with the patient to find the best route back to recovery."