I think my dad's a fuckin loony, loony, loony, loony... crazier than a shit house rat

For 22 years he has believed that there are hidden (winning) codes in the lottery, and all he does in his spare time - for the past 22 years - is attempt to crack these "secret" codes.

The loony even phoned the lottery company, and said to them that there is a man controlling the lottery balls, and keeps deliberately changing them every time he [my dad] cracks the hidden codes. He was being very threatening towards the representative on the phone, and in return [and rightfully so] she threatened to call the police on him.

He turned around to me one time and said, 'I'm scared. They are going to send people out to get me for finding out the scam, so I want to pass this secret knowledge on to you'. Secret knowledge...? The man hasn't won shit except the occasional £10 here and there over 22 years.

Additionally, on bonfire night he was on the toilet [taking a shit I presume], when a firework exploded above the roof. He went berzerk and believed it was lottery assassins firing rockets at him. WTF?

I dread introducing new girlfriends to him because the whack job always has to embarrass me with his lottery conspiracy theories, and attempts to make them see these baloney codes he insists are real. He has also fallen out with family and friends who disagree with his lotto conspiracy theory.

Why does he continue to delude himself with this nonsense? He's always had a mania for money and been very stingy, but Jesus H - surely he should know by now that there's no secret codes.

Do you think the lust for money has made him become delusional, and he's constructed this bizarre fantasy to convince himself that he will strike it rich one day? Or could this be symptomatic of an actual underlying mental illness such as paranoid personality disorder? When I think about it, he has always been a suspicious and paranoid person who tends to misconstrue things and thinks people are out to screw him over - his family included. On many occasions, he even believed that we [his family] were trying to poison his food, and that my mum cheats on him. As such he has this absolute distrust and contempt for anyone.

What do you think?