Pathological gambling runs in families

Pathological gambling runs in families, according to the largest study of its kind to date.
Researchers found that first-degree relatives of pathological gamblers are eight times more likely to develop this problem in their lifetime than relatives of people without pathological gambling.
"Our work clearly shows that pathological gambling runs in families at a rate higher than for many other behavioural and psychiatric disorders," said Donald W Black, professor of psychiatry in the University of Iowa (UI) Carver College of Medicine.
The UI study, which was the largest of its kind in the world to date, recruited and assessed 95 pathological gamblers and 91 control subjects, matched for age, sex, and level of education, from Iowa, as well as 1,075 first-degree adult relatives of the study participants (first-degree relatives include parents, siblings, and children.)

Based on interviews and proxy interview material, the research team determined a gambling diagnosis for every person in the study.
They found that 11 per cent of the gambling relatives had pathological gambling themselves compared to 1 per cent of the control relatives, which means that the odds are about eight times higher in gambling families for pathological gambling to run in those families compared to control families.

When the researchers repeated the analysis to focus on problem gambling - a larger group of people than those with the more narrowly defined pathological gambling - they found that 16 per cent of relatives of the pathological gamblers were problem gamblers compared to 3 per cent of relatives of controls.

The researchers also looked at the relationships between pathological gambling and rates of other psychiatric and behavioural disorders among study participants and showed that relatives of pathological gamblers had higher rates of major depression, bipolar disorder, social anxiety disorder, substance use disorders, PTSD, and antisocial personality disorder.
Using statistical methods the team developed algorithms to determine which disorders are potentially biologically related to the gambling.
They found that antisocial personality, social anxiety disorder, and PTSD were more frequent in the relatives of pathological gamblers independent of whether the relative also had pathological gambling.
"This suggests that pathological gambling may share an underlying genetic predisposition with those disorders," Black said.

The study was published in the Journal of Clinical Psychiatry.