What is an overview of the similarities and differences between the Catholic doctrine of Original Sin and the Reformed doctrine of Total Depravity?

The Catechism of the Catholic Church deals with this subject in §385–412. A couple sections in particular reveal several significant contrasts between Catholic and Reformed theology:

§405: Although it is proper to each individual, original sin does not have the character of a personal fault in any of Adam's descendants. It is a deprivation of original holiness and justice, but human nature has not been totally corrupted: it is wounded in the natural powers proper to it, subject to ignorance, suffering and the dominion of death, and inclined to sin - an inclination to evil that is called concupiscence". Baptism, by imparting the life of Christ's grace, erases original sin and turns a man back towards God, but the consequences for nature, weakened and inclined to evil, persist in man and summon him to spiritual battle.

§407: The doctrine of original sin, closely connected with that of redemption by Christ, provides lucid discernment of man's situation and activity in the world. By our first parents' sin, the devil has acquired a certain domination over man, even though man remains free.

Key points:

• Original sin "is a deprivation of original holiness and justice, but human nature has not been totally corrupted: it is [...] inclined to sin" (405)
• Through Adam's sin, "the devil has acquired a certain domination over man, even though man remains free." (407)
• "Baptism [...] erases original sin and turns a man back towards God." (405)

Now, representing Reformed theology, we turn to the Westminster Larger Catechism:

A25: The sinfulness of that estate whereinto man fell, consisteth in the guilt of Adam's first sin, the want of that righteousness wherein he was created, and the corruption of his nature, whereby he is utterly indisposed, disabled, and made opposite unto all that is spiritually good, and wholly inclined to all evil, and that continually; which is commonly called original sin, and from which do proceed all actual transgressions.

A32: The grace of God is manifested in the second covenant, in that he freely provideth and offereth to sinners a mediator, and life and salvation by him; and requiring faith as the condition to interest them in him, promiseth and giveth his Holy Spirit to all his elect, to work in them that faith, with all other saving graces; and to enable them unto all holy obedience, as the evidence of the truth of their faith and thankfulness to God, and as the way which he hath appointed them to salvation.

A165: Baptism is a sacrament of the New Testament, wherein Christ hath ordained the washing with water in the name of the Father, and of the Son, and of the Holy Ghost, to be a sign and seal of ingrafting into himself, of remission of sins by his blood, and regeneration by his Spirit; of adoption, and resurrection unto everlasting life; and whereby the parties baptized are solemnly admitted into the visible church, and enter into an open and professed engagement to be wholly and only the Lord's.

Corresponding to the points above:

• As a result of Adam's sin, man is "utterly indisposed, disabled, and made opposite unto all that is spiritually good, and wholly inclined to all evil." (25)
• God "promiseth and giveth his Holy Spirit to all his elect, to work in them that faith, with all other saving graces; and to enable them unto all holy obedience" (32)
• Baptism is a "sign and seal of ingrafting into [Christ], of remission of sins by his blood" (165)

Thus we see three significant differences, briefly summarized:

• In Catholicism, man is "wounded," under a "certain domination" of Satan, and "inclined to sin." But in Reformed theology, man is "wholly inclined to all evil" and "utterly indisposed [...] unto all that is spiritually good."
• In Catholicism, "man remains free" from complete domination by sin and Satan, but in Reformed theology, only God has the power to work faith and obedience in the elect.
• In Catholicism, baptism "erases original sin," but in Reformed theology, it is only a "sign and seal" of salvation, not in itself restorative.

As for similarities, we can see several from the context of these sections. Both systems see original sin propagating to all mankind as a result of the sin of our first parents, and this sin has dire effects both on individuals and on the world at large. And in both systems, Christ is the antidote, the New Adam who destroys sin and death.