Article 52 of the Saudi Civil Transactions Law

This article does not set independent rules for the transactions of a person with diminished mental capacity or a person who is insane, but attaches each of them to the rule for a minor:

1. A person with diminished mental capacity: his transactions are treated like the transactions of a minor able to discern.
2. A person who is insane: his transactions are treated like the transactions of a minor unable to discern.

This means that what the law provides for the transactions of a minor able to discern applies to the transactions of a person with diminished mental capacity, and what it provides for the transactions of a minor unable to discern applies to the transactions of a person who is insane. The article does not equate the two cases, but places each in a different position.

The article does not define a person with diminished mental capacity or a person who is insane, and does not state how insanity or diminished capacity is proven.

This article is connected to Article 51, which allows the guardian or executor, once the minor has completed 15 years of age, to hand over to him a portion of his property and authorize him to conduct financial transactions, so that the authorized minor able to discern is treated as one who has reached majority in the transactions he was authorized to conduct. It is also connected to Article 53, which treats the transactions of a spendthrift and of a person of impaired judgment after interdiction like those of a minor able to discern, and treats their transactions before interdiction as valid unless they resulted from exploitation or collusion. So a person with diminished mental capacity, and a spendthrift and a person of impaired judgment after interdiction, are all attached to the minor able to discern.

If a member of your family has a condition that affects his judgment and concluded a contract, consult a lawyer who specializes in personal status or civil cases to assess his position.