Harry Stack Sullivan

Harry Stack Sullivan and the Therapy of Connection

Harry Stack Sullivan is one of the forgotten figures in 20th century psychology, less mythologised than Freud, Jung, and Rogers. Yet Sullivan’s ideas, forged in the early decades of American psychiatry, remain relevant in today’s world of fractured relationships, digital isolation, and rising anxiety and depression. One of Sullivan’s key insights was deceptively simple: ‘mental health is shaped not within the self, but between selves’.

Sullivan called his approach Interpersonal Psychiatry, and it was influential in his time. He argued that personality is primarily formed through relationships. “We are all more simply human than otherwise,” Sullivan wrote, emphasising that most of human experience is shared.

Psychiatry as a Social Science

Born in 1892, Sullivan came into psychiatry when it was dominated by biological determinism and Freudian theories. However, Sullivan, influenced saw the development of mental illness not as a defect of the brain or a failure of libido, but as a disturbance in interpersonal functioning.

In his time as therapist he worked extensively with patients diagnosed with schizophrenia, and unlike many of his contemporaries, he treated them with dignity and curiosity. He believed that even the most severe symptoms could be understood as attempts to manage extreme anxiety, typically rooted in early relational trauma and social rejection.

The Self as a Social Product

Sullivan’s theory of personality development centres on the idea that the self-system emerges from interactions with others. From infancy onward, we learn to manage anxiety by adapting to the expectations and reactions of our caregivers. These adaptations become thinking and behavioural patterns that shape how we relate to others and ourselves.

In his therapy, Sullivan’s approach is not just exploring the unconscious, but to focusing on the ‘here-and-now’ dynamics of the therapeutic relationship. The therapist becomes a participant and observer, helping the client notice how they relate, withdraw, defend, or seek approval, all in real time in the session.

Anxiety and Security Operations

Sullivan introduced the concept of ‘security operations’, the strategies we use to reduce our anxiety and maintain a sense of safety in relationships. These include denial, avoidance, and idealisation. While these security operations may protect the self and reduce anxiety in the short term, they often distort reality and hinder the genuine connection we seek with others.

For example, an individual who constantly agrees with others may be using “consensual validation” to avoid any chance of conflict. In therapy, the goal is to understand the origin of this behaviour and thinking, and help the client find the motivation to adopt an alternative pattern in the safety of the therapeutic alliance.

Applications in Today’s Mental Health Landscape

In our modern times when loneliness, social isolation, and low self-acceptance are major problems in life, Sullivan’s interpersonal lens offers a powerful framework for understanding mental illness. Sullivan would see

• Depression as a collapse of meaningful connection, where the self feels unworthy or invisible.

• Anxiety disorders as hypervigilance to perceived relational threats—rejection, judgment, abandonment.

• Personality disorders as rigid self-systems formed in response to chaotic or invalidating relationships earlier in life.

Sullivan’s approach encourages us to look beyond symptoms and ask: 

“How do we relate to others? “

“What relational patterns are keeping you stuck or making you anxious? “

“What new ways of connecting can be explored and practiced here, together in therapy?”

Therapy as a Human Encounter

Sullivan believed that healing occurs not through interpretation or technique alone, but mostly through authentic interpersonal engagement. His approach inspires the therapist to be curious, present, attuned, and willing to be affected by the client.

Sullivan’s approach resonates with many contemporary relational and psychodynamic therapies, which emphasize the therapeutic relationship as the vehicle for change. In a world increasingly mediated by screens and algorithms, Sullivan’s insistence on the importance of human connection feels the opposite of new developments in psychotherapy such as text-based online therapy and telehealth sessions.

A Legacy of Empathy

Though Sullivan died in 1949, his influence lives on in the approach many psychotherapists employ today. Many of his ideas laid the groundwork for modern individual psychotherapy and group therapy. He saw the therapeutic encounter not as a correction, but as a collaboration, a shared journey toward understanding and connection.