In order to be diagnosed, an individual must have at least four of the following symptoms in a 12-month period:
Needs to gamble with increasing amounts of money in order to achieve the desired excitement
Is restless or irritable when attempting to cut down or stop gambling
Has made repeated unsuccessful efforts to control, cut back, or stop gambling
Is often preoccupied with gambling (e.g., having persistent thoughts of reliving past gambling experiences, handicapping or planning the next venture, thinking of ways to get money with which to gamble)
Often gambles when feeling distressed (e.g., helpless, guilty, anxious, depressed)
After losing money gambling, often returns another day to get even ("chasing" ones losses)
Lies to conceal the extent of involvement with gambling
Has jeopardized or lost a significant relationship, job, education, or career opportunity because of gambling
Relies on others to provide money to relieve desperate financial situations caused by gambling

Factors that lead to gambling addiction
Mayo Clinic specialists state that compulsive gambling may be result from biological, genetic, and environmental factors, such as:
mental health disorders (the presence of substance use disorders, personality disorders, emotional states)
age and sex (usually found in youth or middle-aged people, and more common to men than women)
impact on family or friends
personality traits
drugs with rare side-effects (for example, antipsychotic medications or dopamine agonists).Other studies add the following triggers to the mentioned above:
traumatic conditions
job-related stress
solitude
other addictionsIf not treated, problem gambling may cause very serious and lasting effects on an individuals life:
relationship related issues
problems with money, bankruptcy
legal problems, imprisonment
health problems
suicide, including suicidal thoughts and attempts

Suicide rates
A gambler who does not receive treatment for pathological gambling when in a desperation phase may contemplate suicide.
In its 72nd World Health Assembly held on Saturday, May 25, 2019, ‘gaming disorder’ was recognized as an official illness. The 194-member meet added excessive gaming to a classified list of diseases as it revised its International Statistical Classification of Diseases and Related Health Problems (ICD-11). North America
In the United States, the percentage of pathological gamblers was 0.6 percent, and the percentage of problem gamblers was 2.3 percent in 2008. Studies commissioned by the National Gambling Impact Study Commission Act has shown the prevalence rate ranges from 0.1 percent to 0.6 percent. Nevada has the highest percentage of pathological gambling; a 2002 report estimated 2.2 to 3.6 percent of Nevada residents over the age of 18 could be called problem gamblers. Also, 2.7 to 4.3 percent could be called probable pathological gamblers.According to a 1997 meta-analysis by Harvard Medical Schools division on addictions, 1.1 percent of the adult population of the United States and Canada could be called pathological gamblers. A 1996 study estimated 1.2 to 1.9 percent of adults in Canada were pathological. In Ontario, a 2006 report showed 2.6 percent of residents experienced "moderate gambling problems" and 0.8 percent had "severe gambling problems". In Quebec, an estimated 0.8 percent of the adult population were pathological gamblers in 2002.