The tobacco epidemic is one of the biggest public health threats the world has ever faced, killing more than 7 million people a year (WHO).

People with psychosis are more likely to smoke compared to the general population and it is believed that this could have a negative impact on cognitive functioning.

A recent study, published in the American Journal of Psychiatry, has analysed the association between peoples’ current smoking behaviour and performance on cognitive tasks, whether a longitudinal link between smoking behaviour and cognitive functioning exists, and smoking cessation can improve peoples’ cognitive functioning.

The researchers compared people with non-affective psychosis, their unaffected siblings and healthy individuals.

Results found that:

• At baseline, 66.6% of the patients smoked, compared with 38.3% of the siblings and 25.2% of the control subjects.
• Among the patients, there was a link between smoking and lower performance on cognitive processing speed
• Within the unaffected sibling group, there exists a negative link between smoking status and working memory, reasoning and problem-solving.
• Within the health control group, there was a significant association between smoking behaviour and lower cognitive processing speed.
• There is an association between smoking cessation and better performance on processing speed among the patients who quit smoking. The results show that even changes in the number of cigarettes smoked per day were linked with cognitive functioning improvement.

Overall the results show that smoking is positively linked with lower performance in many cognitive functions for all of the groups tested. The evidence for the link between smoking cessation/ reduction and cognitive functioning improvement highlights the benefits of incorporating smoking cessation support into evidence-based interventions for people with psychosis.

Harmful alcohol use is known to increase the risk of alcohol dependence as well as physical conditions such as hypertension, cardiovascular disease, and cirrhosis.

Alcohol use disorder (AUD) is a common co-occurring disorder in people with mental health conditions. This can negatively impact the course and treatment outcomes.

Researchers in Singapore have investigated the prevalence and nature of hazardous alcohol use among those with schizophrenia and depressive disorders taking into account sociodemographic and clinical factors, and severity of depression and anxiety. They also assessed the link between alcohol use and the quality of life of psychiatric patients. 

A total of 310 patients participated in the study which involved completing a set of clinical measures. 

Results found that:

• The prevalence of hazardous alcohol use was 18.8% among patients with depression and 6.4% among patients with schizophrenia. 

• Patients who were unemployed were more likely to engage in hazardous drinking compared to participants who were students or employed.
• Patients with severe anxiety were 9 times more likely to engage in hazardous alcohol use than those with mild anxiety
• Patients with severe depression were 5 times more likely to engage in hazardous alcohol use than those with minimal depression
• Current smokers and ex-smokers were about 15 times and 13 times more likely to engage in hazardous alcohol use as compared to non-smokers
• Harmful alcohol consumption was particularly associated with lower quality of life in the physical health domain.

Overall the research emphasised the link between severity of depression and the risk of hazardous alcohol intake. This highlights the importance of both conditions to be treated jointly and for thorough screening to help with early identification of issues.