Angry cognitive bias, trait aggression and impulsivity in substance users

Area of Science:

• Cognitive psychology
• Neuroscience
• Substance abuse research

Background:

• Cognitive theory posits aggressive individuals anticipate angry responses to ambiguous situations.
• Methylenedioxymethamphetamine (MDMA) use is linked to increased aggression, potentially due to reduced serotonin (5-HT) release.
• A 5-HT challenge may differentially impact anger-related cognitive bias in MDMA users and non-users.

Purpose of the Study:

• To determine if anger/aggression measures correlate with processing angry material and generating aggressive responses.
• To investigate the effect of a tryptophan challenge on angry cognitive bias in abstinent MDMA users and controls.

Main Methods:

• Recruited 32 current MDMA users (abstinent 3 weeks), 32 ex-users (abstinent >1 year), and 32 non-users.
• Administered trait measures and state measures before and 5 hours after an amino acid drink (tryptophan-depleted or augmented).
• Assessed cognitive bias using a computer task involving ambiguous stories, measuring reading times and written responses.

Main Results:

• Faster processing of angry versus non-angry reactions indicated angry cognitive bias.
• Trait anger and aggression correlated with processing angry material, especially in current MDMA users.
• Tryptophan depletion tended to increase aggressive content, and trait aggression correlated with written aggression.

Conclusions:

• Angry cognitive bias is present in substance users and not exclusive to MDMA.
• Individuals with high trait aggression are more prone to expecting angry reactions and generating aggressive content.