Substance use disorders and suicide attempts in bipolar subtypes

Area of Science:

• Psychiatry
• Neuroscience
• Clinical Psychology

Background:

• Bipolar disorder (BD) has high suicide attempt rates.
• Substance use disorders (SUD) are known risk factors for suicidal behavior in BD.
• Differences in SUD as a risk factor across BD subtypes are not well understood.

Purpose of the Study:

• To investigate the association between SUD and suicidal behavior in Bipolar I (BD-I) and Bipolar II (BD-II) disorder.
• To explore clinical factors influencing the relationship between SUD and suicide attempts in BD subtypes.

Main Methods:

• Study included adults with major depressive episodes in BD-I (N=96) and BD-II (N=42) with and without SUD history.
• Logistic regression analyzed the association between SUD and suicide attempt history by BD type.
• Exploratory analyses examined other clinical characteristics' effects.

Main Results:

• SUD were significantly associated with suicide attempts in BD-I, but not BD-II.
• In BD-I, alcoholism's link to suicide attempts was mediated by aggression; earlier BD onset amplified this association.
• Other drug use disorders in BD-I were linked to higher impulsivity, hostility, and aggression.
• Comorbid alcohol and drug use disorders in BD-I showed a multiplicative increase in suicide attempt risk (97% attempt rate).

Conclusions:

• SUD represent a significant risk factor for suicidal behavior, particularly in BD-I.
• Aggression, impulsivity, and early onset are key factors mediating the SUD-suicidality link in BD-I.
• Targeting SUD and aggressive traits is crucial for preventing suicidal behavior in BD-I.