Alexithymia is a mediating factor in the relationship between adult attachment and severity of depression and social anxiety

Major depressive disorder (MDD) and social anxiety disorder (SAD) are commonly occurring conditions, either alone or together (MDD-SAD). Recent research linked insecure attachment and alexithymia to MDD and/or SAD, indicating that the way affected individuals relate interpersonally and their ability to identify and communicate emotions are pertinent issues. The current study investigated the mediating role of alexithymia in the relationship between insecure attachment and severity of MDD and SAD symptoms.Using the SCID-I, participants (N=159) were identified as MDD-only (n=43), MDD-SAD (n=56), or a healthy control (n=60). Participants completed measures of adult attachment, depression, social anxiety and alexithymia (defined as difficulty identifying and describing feelings). A two-step mediation analysis approach recommended by Shrout and Bolger determined if alexithymia mediates the relationship between attachment-depression and attachment-social anxiety.While alexithymia was high in MDD-only and MDD-SAD groups, individuals with MDD-SAD had significantly greater difficulty describing feelings. Alexithymia was a full mediator between attachment avoidance and depression, but only a partial mediator between attachment anxiety and depression. Meanwhile, alexithymia was a partial mediator for both attachment dimensions and social anxiety.Causal inferences regarding insecure attachment, alexithymia, and MDD and SAD cannot be assumed given the cross-sectional data. The 'externally oriented thinking' component in alexithymia was also excluded from analyses due to low reliability.The results suggest emotional awareness and expression play a role in the illness severity for MDD and SAD-particularly in those with high attachment avoidance, offering a possible target for treatment and prevention strategies.