Sadiq Khan has called for the partial decriminalisation of cannabis, arguing that a new report published by the London Drugs Commission (LDC) yesterday provides a “compelling, evidence-based case” for it.

The independent report makes 42 recommendations in total – including the removal of natural cannabis from the Misuse of Drugs Act (MDA), arguing that the current sentencing options, particularly around personal possession, “cannot be justified” and that the wholesale prohibition under the MDA “treats cannabis in a manner that is disproportionate to its harms”.

Although the report clearly outlines the downsides of the Class B drug – including its addictive qualities – it argues that the contents and timing of education around its uses can help plug knowledge gaps and decrease the risks associated with it.

The report also suggests that decriminalising cannabis would mean people who use it for medicinal purposes but can’t afford to get a private prescription wouldn’t be penalised.

David Raynes, of the National Prevention of Drugs Alliance (NPDA), however, said any reduction in the legal consequences around cannabis would wrongly send the message that “cannabis was less harmful”.

Angela Rayner, the deputy prime minister, also said the recommendations in the report were “not the government position and we are not going to be changing our policy”.

Here, we take a look at the potential health benefits and side-effects of the Class B drug.

While it’s illegal to use cannabis for recreational purposes in the UK, in some cases medicinal cannabis may be prescribed for people with certain conditions. Currently, cannabis-based medicine is not widely available on NHS prescription in England.

As it stands, it is only likely to be prescribed to:

• Children and adults with rare, severe types of epilepsy

• People with muscle stiffness and spasms caused by multiple sclerosis (MS)

• And adults with vomiting or nausea caused by chemotherapy

The NHS also stresses that this type of medication is only considered when other treatments are not suitable or have not worked.

Cannabis-based medicine Sativex is in some cases used to treat multiple sclerosis (MS) symptoms, such as muscle stiffness and spasms (or spasticity). It comes in mouth spray form and contains two chemicals – tetrahydrocannabinol (THC) and cannabidiol (CBD) – from the cannabis plant.

According to the MS Society, the medication doesn’t work for everyone, but when people use Sativex, around seven in 10 see their spasticity reduced by 20%.

2. The jury is out on how it helps long-term pain

There have been various studies examining the effects cannabis-based medication has on those who suffer with chronic pain, and there is some evidence that medical cannabis can help ease certain types of pain, but more evidence is needed.

One study published in The Lancet – that began in 2012 and included a four-year follow-up – found that, compared with those who didn’t use cannabis, those who did had a greater pain severity score, a greater pain interference score, lower pain self-efficacy scores, and greater generalised anxiety disorder severity scores, meaning there was no evidence it improved their pain.

Those having chemotherapy may benefit from cannabis-based medication Nabilone, a drug that comes in capsule form. It is used to treat the nausea and vomiting caused by the cancer treatment and works by affecting the area of the brain that controls these reflexes.

Coming in purified liquid form, Epidyolex is a medication for epilepsy that contains cannabidiol (CBD). It is usually only prescribed to those with Lennox-Gastaut syndrome or Dravet syndrome.

The UK Addiction Treatment Centres cites that 11% of users will develop a cannabis addiction, with that figure rising to 16% if you used cannabis as a teen.

It attributes this to THC, the main psychotic element found in cannabis, which disrupts mental and physical functions. It defines cannabis addiction as an induced state through continued cannabis use over time.

If smoked with tobacco, cannabis can impact your breathing, make you wheeze and cough, and can worsen asthma symptoms if you have it.

According to Talk to Frank, vaping cannabis chemicals is generally less harmful to your lungs, because smoking creates harmful toxins that can cause cancer, lung disease, heart disease and stroke. Though, it warns, there’s no way of knowing whether a THC vape has been prepared with other harmful substances, as it won’t have gone through the same quality controls as legal vapes.

Per the NHS, there is evidence that regular cannabis use and the use of THC cannabis products in some people can increase the risk of developing a psychotic illness, such as schizophrenia.

There are various mental health risks associated with cannabis use. Not only can it impact your mood, motivation and memory, it can make you anxious, panicky, aggressive, cause paranoia and disturb your sleep.

As well as increasing the heart rate, cannabis can raise blood pressure immediately after use. More research is needed to fully understand the impact cannabis has on the cardiovascular system, but the US Centers for Disease Control and Prevention (CDC) says it could increase the risk of stroke, heart disease, and other vascular diseases, as well as heart attacks.

As touched on above, smoking cannabis may also increase the risk of developing lung cancer. Even if you smoke less tobacco than those who smoke regular cigarettes, the combination of the two substances, as well as how deep you inhale and how long you hold the smoke in your lungs, can impact your long-term health.

Although there’s no conclusive evidence that using cannabis leads to erectile dysfunction, some studies have suggested a link between the drug and impotence.

Similarly, while some studies have shown cannabis use negatively impacts fertility in men and women, there is no conclusive evidence.

That said, scientists have suggested that continuous exposure to THC may cause ovulation delay in women, may reduce sperm count in men, and could exacerbate existing fertility problems.

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