Does the presence of a dipole moment in a molecule tend to increase or decrease the strength of intermolecular interactions?

Yes, the presence of a dipole moment in a molecule tend to increase the strength of inter-molecular interactions.

Explanation:

Dipole moment:

It is a vector quantity and is used to measure the  distance between the two opposite charges.

The stronger the dipole moment, the greater the inter-molecular forces. The inter-molecular forces are formed between the molecules and their strength decreases as the distances between the molecules increases. Like the inter-molecular forces are stronger in liquids and are weaker in gases due to the increased distances between the molecules in gases.