Meet Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for principal OCD. These participants will complete clinician interviews, self-report questionnaires, and receive the Decision-Making Tasks Intervention.

No current DSM-5 diagnosis. These participants will also complete clinician interviews, self-report questionnaires, and receive the Decision-Making Tasks Intervention.

All participants will receive a structured diagnostic assessment and complete self-report questionnaires about cognitive factors, decision-making styles, and anxiety/mood symptoms. They then will be guided through three judgment and decision-making (JDM) paradigms (the Risk and Ambiguity Task, the Beads Task, and the Balloon Analogue Risk Task), each of which each has been modified to differ by whether the likelihood of potential adverse outcomes is provided (or whether it remains ambiguous).

In the Risk and Ambiguity Task participants make repeated choices between a certain payoff vs. a gamble. On low ambiguity trials, the likelihood of the gamble is known (i.e., "risky" lottery). On high ambiguity trials, the likelihood of the gamble is unknown (i.e., "ambiguous" lottery). Ambiguity aversion = (number of 50% risky lotteries chosen / total number of 50% risky lotteries) - (# of ambiguous lotteries chosen / total number of ambiguous lotteries).

In the BART participants blow up a series of virtual balloons. With each pump: (a) they earn 5 cents that accumulate in a temporary reserve, but (b) the likelihood of the balloon exploding increases. When this occurs participants lose the money in their temporary reserve. At any time, participants can choose to transfer their earnings to a permanent savings bank (and move to the next balloon). Thus, participants weigh the likelihood of the negative outcome (i.e., the balloon exploding and losing money) with the potential gains (i.e., 5 cents per pump). In the low ambiguity version of the task, the likelihood of the balloon exploding is known. In the high ambiguity version, the likelihood of the balloon exploding is unknown. The average adjusted pump score = average number of pumps on trials in which the balloons did not explode.

The Beads Task is a probabilistic inference task in which participants gather as much information (i.e., beads) as they desire before feeling "certain" enough to decide from which jar the beads have come. Participants will start off with a fixed amount of money, and invest money for each bead requested. If they answer correctly, the money earned will be transferred to a savings bank; if incorrect, they lose any earnings from that trial. Thus, participants must consider the tradeoff between the number of beads they choose and their accuracy as they decide. In the low ambiguity version of the task, the ratio of colored beads inside the jar is known. In the high ambiguity version, the ratio of colored beads inside the jar is unknown.